TheFishMan65
New member
I set my overflow even with the trim, water level must therefore be higher than the trim. The catch is the tank must be level. So IMHO go maybe 1/2-1/4 inch than than lower edge of the trim.
Silent and Failsafe Overflow System
- Thread starter JohnL
- Start date
RocketSurgeon
New member
simple reason for larger bulkheads and pipes, less chance of being blocked by a snail, or fish.
RocketSurgeon
New member
I believe mine is about a 1/4" higher than the bottom of the trim. When power is off, I still do not see a water line, as it is hidden by the trim.
CreativeGuy
Creature Morpheus ...
Okay, here we go .... Part One of Three for the post.
I am trying respectfully to ask about several items related to the overflow system of a new 570g SPS reef tank as there are a series of pumps and associated piping systems or circuits involved:
1)for verification on overflow pipe sizing is appropriate for the various flows
2)whether the linear inches of overflow for the coast to coast system shall be sufficient
3)the proposed heights of the discharges
4)any issues or items I may be overlooking or not considering
During the past few days I have tried to begin to develope a web page for this project, which is called Creature Morpheus because it has “morphed” into a Monster. For anyone interested in knowing more, they can visit the we site: http://creaturemorpheus.com. Within this post I wish to relate to the questions above.
EXTERIOR OVERFLOW BOXES: There are two planned external overflow boxes, both with approximately 33” and 18” linear inches respectfully of overflow each (50” total). The interior dimensions are 4.5” wide and 15” deep. Based on the calculator from reef central, 50” linear inches would have a recommended flow of 3,300 gph, which is substantially lower than proposed/design if inclusive of the multiple closed loops.
MAIN DISPLAY TANK GENERAL FLOW and OVERFLOWS: Within the main display tank there are 8 discharges from the two overflow boxes. The design is intended to incorporate multiple DC pumps with changing dynamic flow patterns within the tank by varying flow of the distributing lines in the tank. Objective being “quality” of dynamic flow rather than “quantity”.
Flows from the main display tank to the filtration system is expected to remain reasonably constant, once all the supplied components are balanced, the targeted expected range shall be 2,400 gph of discharge (4 changes per hour) and equally returned to the main display tank by two pumps.
Additionally there will be four closed circulation loops which dynamically change depending on programming. Two of the four circuits shall be on the bottom of the tank (piping under the sand with four nozzles each), each with an average total of the two 3000 gph. A third for under the raised rock scape to suspend and clear ditrious materails with an expected flow TBD, but estimating 600 gph at this time. The forth loop is for an Oceans Motions 4-way (at approximately 1,000 gph). These piping systems are detailed and/or explained further in the next section. This would total out about 6000 gph of flow through the overflows.
There are two MP60w ES VorTech units at opposing sides of the main tank for additional dynamic flow within the tank, capable of adding 10,000 to 14,000 gph of water movement to the tank. The tank's shape was designed to suit the location and layout of the home (visible from 5 sides), but also to assist in circulating water from the opposing VorTech units. This coupled with use of eductors at most other outlets to close to double their water movement, should provide means to generate quality flow patterns.
As I am new and having trouble posting images here, I am posting the web link to the images,
http://creaturemorpheus.com/CreatureMorpheus/Circulation_within_the_Main_Display_Tank_570g.html
I am trying respectfully to ask about several items related to the overflow system of a new 570g SPS reef tank as there are a series of pumps and associated piping systems or circuits involved:
1)for verification on overflow pipe sizing is appropriate for the various flows
2)whether the linear inches of overflow for the coast to coast system shall be sufficient
3)the proposed heights of the discharges
4)any issues or items I may be overlooking or not considering
During the past few days I have tried to begin to develope a web page for this project, which is called Creature Morpheus because it has “morphed” into a Monster. For anyone interested in knowing more, they can visit the we site: http://creaturemorpheus.com. Within this post I wish to relate to the questions above.
EXTERIOR OVERFLOW BOXES: There are two planned external overflow boxes, both with approximately 33” and 18” linear inches respectfully of overflow each (50” total). The interior dimensions are 4.5” wide and 15” deep. Based on the calculator from reef central, 50” linear inches would have a recommended flow of 3,300 gph, which is substantially lower than proposed/design if inclusive of the multiple closed loops.
MAIN DISPLAY TANK GENERAL FLOW and OVERFLOWS: Within the main display tank there are 8 discharges from the two overflow boxes. The design is intended to incorporate multiple DC pumps with changing dynamic flow patterns within the tank by varying flow of the distributing lines in the tank. Objective being “quality” of dynamic flow rather than “quantity”.
Flows from the main display tank to the filtration system is expected to remain reasonably constant, once all the supplied components are balanced, the targeted expected range shall be 2,400 gph of discharge (4 changes per hour) and equally returned to the main display tank by two pumps.
Additionally there will be four closed circulation loops which dynamically change depending on programming. Two of the four circuits shall be on the bottom of the tank (piping under the sand with four nozzles each), each with an average total of the two 3000 gph. A third for under the raised rock scape to suspend and clear ditrious materails with an expected flow TBD, but estimating 600 gph at this time. The forth loop is for an Oceans Motions 4-way (at approximately 1,000 gph). These piping systems are detailed and/or explained further in the next section. This would total out about 6000 gph of flow through the overflows.
There are two MP60w ES VorTech units at opposing sides of the main tank for additional dynamic flow within the tank, capable of adding 10,000 to 14,000 gph of water movement to the tank. The tank's shape was designed to suit the location and layout of the home (visible from 5 sides), but also to assist in circulating water from the opposing VorTech units. This coupled with use of eductors at most other outlets to close to double their water movement, should provide means to generate quality flow patterns.
As I am new and having trouble posting images here, I am posting the web link to the images,
http://creaturemorpheus.com/CreatureMorpheus/Circulation_within_the_Main_Display_Tank_570g.html
Last edited:
CreativeGuy
Creature Morpheus ...
Part Two of Three for the Post .....
Please see the CAD drawings for the Display tank (linked above) and the Flow Diagram http://creaturemorpheus.com/CreatureMorpheus/System_Flow.html for a better understanding of the below discussion.
(A) TWO MAIN GRAVITY DISCHARGES FROM THE TANK: Two main separate re-circulation pipe systems (redundancy) which supply/return to the display tank. There are two gravity drainage pipes M1 and M2 with “target” from the tanks at 1,200 gph with a maximum expectation of 1,800 gph. (total would be a target of 2 x 1,200 = 2,400 gph or maximum of 2 x 1,800 gph = 3,600 gph in both lines). There is a third back-up or overflow line to be plumbed per the silent overflow design.
Based on engineering information of roof drainage piping, a 1.5” pipe at 5 ft/sec (maximum recommended without detrimental noise and effects) can handle 1,860 gph. It has been indicated that under full siphon the pipes can even handle substantially more flow depending on various factors like height or head differential and piping components (elbows, valves, losses). The central filtration system located in the crawl space below the main floor (which has approximately 7 feet of vertical differential and 20 feet of horizontal) with expectations of each pipe having two union valves for servicing, (5) 90 elbows, 35 feet of pvc pipe.
After the filtration, the water is then pumped back up to the main tank via two other return lines (1.5” each) to near or just below surface return manifolds with 6 heads each on 6” of 3/4” loc-line.
(B) BOTTOM CIRCULATION: There are two DC variable controlled pumps dedicated for closed loop circulation (1.5” then split into 4 leads (1”) with fittings and adjustable eductors heads each likely performing at closer to a 3/4” discharge) strategically placed in the corners or front of the tank (under the sand) to limit dead zones and cause a barrel roll affect to force the surface water back towards the coast to coast overflow boxes. These will also be discharged from the rear overflow boxes via 1.5” lines. The will be dynamic/variable flow patterns created and programmed. The targeted maximum anticipated flow would be 300 to 450 gph per head (total for each loop range of 1,200 to 1,800 gph). With the use of eductors, the anticipated water circulation maybe equated to doubled. As these shall be DC variably controlled, as well as lines further split at the heads or throttled by small inline valves for the purpose of future flexibility and control dynamics.
As a closed loop system, anticipating connections, fittings and discharge nozzles, pipe and head losses, and moving potentially 1,500 to 1,800 gph, the appropriate sizing would again appear to be 1.5”. In many cases, the discharge pipe from the tank or the supply side of the pump is often up-sized to the next size, in this case 2”. Does someone have any experience or technical information to confirm the size at 1.5” or should they be up-sized to 2”?
(C) UNDER ROCK FLOW: The rockscape is expected to be suspended 2” to 3” above the sand such as on acrylic pegs with the intention of having open water under the rock and above the sand bottom, to allow for flow for purposes of clearing diterous material. Another closed loop with either a manifold with dispersing nozzles, or length of circular flow nozzles (loc-line) to inject under at a volume high enough to suspend the diterious material and low enough not to disrupt the sand (sand to be of a larger sieve size under the rock). Depending on the number of nozzles and length of pipe, the flow shall have to be proportioned and selection of an appropriate DC pump as to have flexibility and possibly create a bit of dynamic environment and only purge periodically. Likely expecting to size the discharge pipe to 1.25” (although the standard fittings, valves and pipe are probably cheaper to keep at 1.5”) and feed with either a 1.25” or just a 1” line depending on final design and selection. Anyone know what kind of flow rate would work well under a rock application like this?
(D) OCEANS MOTIONS 4-Way: The inlet and outlet of the OM 4-way is 1.5”, and therefore am expected to plumb for the 1.5” size for the overflow box discharge. Returns are expected to be 1” and an anticipated target flow of between 800 and 1,000gpm. Final design and practical application shall review with Paul from Oceans Motions, as well as the selection of an appropriate DC pump.
(E) Safety Drain Overflow: There is a high water safety overflow which drains down directly into a sanitary sewer drain and is set at 1” below the top of the tank perimeter (1/2” above the main discharge drains). This shall also be 1.5” in diameter. No water should enter this pipe except for an emergency or malfunction, and therefore has a sensor alarm should water be detected.
In summary, all of the expected discharges shall be 1.5” in pipe sizing.
Would you concur that these would be sufficient for the proposed tank?
Appreciate your opinion Bean (or others, should you wish to chime in).
Please see the CAD drawings for the Display tank (linked above) and the Flow Diagram http://creaturemorpheus.com/CreatureMorpheus/System_Flow.html for a better understanding of the below discussion.
(A) TWO MAIN GRAVITY DISCHARGES FROM THE TANK: Two main separate re-circulation pipe systems (redundancy) which supply/return to the display tank. There are two gravity drainage pipes M1 and M2 with “target” from the tanks at 1,200 gph with a maximum expectation of 1,800 gph. (total would be a target of 2 x 1,200 = 2,400 gph or maximum of 2 x 1,800 gph = 3,600 gph in both lines). There is a third back-up or overflow line to be plumbed per the silent overflow design.
Based on engineering information of roof drainage piping, a 1.5” pipe at 5 ft/sec (maximum recommended without detrimental noise and effects) can handle 1,860 gph. It has been indicated that under full siphon the pipes can even handle substantially more flow depending on various factors like height or head differential and piping components (elbows, valves, losses). The central filtration system located in the crawl space below the main floor (which has approximately 7 feet of vertical differential and 20 feet of horizontal) with expectations of each pipe having two union valves for servicing, (5) 90 elbows, 35 feet of pvc pipe.
After the filtration, the water is then pumped back up to the main tank via two other return lines (1.5” each) to near or just below surface return manifolds with 6 heads each on 6” of 3/4” loc-line.
(B) BOTTOM CIRCULATION: There are two DC variable controlled pumps dedicated for closed loop circulation (1.5” then split into 4 leads (1”) with fittings and adjustable eductors heads each likely performing at closer to a 3/4” discharge) strategically placed in the corners or front of the tank (under the sand) to limit dead zones and cause a barrel roll affect to force the surface water back towards the coast to coast overflow boxes. These will also be discharged from the rear overflow boxes via 1.5” lines. The will be dynamic/variable flow patterns created and programmed. The targeted maximum anticipated flow would be 300 to 450 gph per head (total for each loop range of 1,200 to 1,800 gph). With the use of eductors, the anticipated water circulation maybe equated to doubled. As these shall be DC variably controlled, as well as lines further split at the heads or throttled by small inline valves for the purpose of future flexibility and control dynamics.
As a closed loop system, anticipating connections, fittings and discharge nozzles, pipe and head losses, and moving potentially 1,500 to 1,800 gph, the appropriate sizing would again appear to be 1.5”. In many cases, the discharge pipe from the tank or the supply side of the pump is often up-sized to the next size, in this case 2”. Does someone have any experience or technical information to confirm the size at 1.5” or should they be up-sized to 2”?
(C) UNDER ROCK FLOW: The rockscape is expected to be suspended 2” to 3” above the sand such as on acrylic pegs with the intention of having open water under the rock and above the sand bottom, to allow for flow for purposes of clearing diterous material. Another closed loop with either a manifold with dispersing nozzles, or length of circular flow nozzles (loc-line) to inject under at a volume high enough to suspend the diterious material and low enough not to disrupt the sand (sand to be of a larger sieve size under the rock). Depending on the number of nozzles and length of pipe, the flow shall have to be proportioned and selection of an appropriate DC pump as to have flexibility and possibly create a bit of dynamic environment and only purge periodically. Likely expecting to size the discharge pipe to 1.25” (although the standard fittings, valves and pipe are probably cheaper to keep at 1.5”) and feed with either a 1.25” or just a 1” line depending on final design and selection. Anyone know what kind of flow rate would work well under a rock application like this?
(D) OCEANS MOTIONS 4-Way: The inlet and outlet of the OM 4-way is 1.5”, and therefore am expected to plumb for the 1.5” size for the overflow box discharge. Returns are expected to be 1” and an anticipated target flow of between 800 and 1,000gpm. Final design and practical application shall review with Paul from Oceans Motions, as well as the selection of an appropriate DC pump.
(E) Safety Drain Overflow: There is a high water safety overflow which drains down directly into a sanitary sewer drain and is set at 1” below the top of the tank perimeter (1/2” above the main discharge drains). This shall also be 1.5” in diameter. No water should enter this pipe except for an emergency or malfunction, and therefore has a sensor alarm should water be detected.
In summary, all of the expected discharges shall be 1.5” in pipe sizing.
Would you concur that these would be sufficient for the proposed tank?
Appreciate your opinion Bean (or others, should you wish to chime in).
RocketSurgeon
New member
Use 2" for emergency. I'd use 1.5" for siphon and open channel.
CreativeGuy
Creature Morpheus ...
Part Three of Three for the Post
OVERFLOW BOXES:
Here is a link to the tank dimensions. http://www.projectmorpheus.me/CreatureMorpheus/570g_Tank_Specs_%26_Dimensions.html
As mentioned above, I am limited to 50” of coast to coast overflows, which by Reef Central's calculator has a recommended overflow of 3,300 gph. Where as the exiting target flow to the filtration system is approximately 2,400 gph plus an additional closed loop circulation of 3,600 gph. The potential maximum flows could be as much as 3,600 gph to the filtration system and additionally possibly up to 5,600 gph of closed loop circulation.
The display tank has an overall design of 34” high and has a 1.625” laminated bottom and 3/4” glass top reinforcement. The planned top edge to the external overflow boxes is 1.75” down from the top (which would maintain a 3/4” of height (gap) below the top perimeter reinforcement). Expectations of the water flowing over into the overflow boxes would be 1/4” to 3/8” of an inch, an expected maximum 1/2” (would this assumption be accurate?). In reading the recent post, some have had 1” flowing over the weirs of the overflow boxes.
As I am inexperienced and unfamiliar with tank overflow dynamics, I was hoping some people may have knowledge and experience to draw upon and confirm, indicate potential errors or situations, or provide insight or suggestions on where or who I could further investigate matters. Just my logical thoughts regarding the two major segments of “re-circulation” (that flow actual “leaving” the tank by gravity and going to the filtration system) and the closed loop “circulation” - where the water does not “leave” the system or change its water surface elevation. The water being “returned” to the tank from the filtration by pump could potentially have a greater effect on the water surface elevation. Hence, my thoughts were to keep the “circulation” discharges submerged (lower about 1” of the surface) and in a separate external overflow box, rather than the overflow box containing the main exiting discharges to the filtration system. The one downfall to this I see if one of the circulation lines leaks or is compromised, it could potentially lower the water level to below the primary overflow box (containing the re-circulation lines to the filtration). One thought was to keep the second overflow box (containing the circulation pipes) at an elevation 1/4” higher, in that way if there was an issue, and the level dropped because of the circulation lines, the main supply/returns would not be starved.
A main objective was not to have holes within the main display tank and the discharges to occur from only the external overflow boxes. However, based on the potential discharged flow and the 50” of limited inches of overflow, this objective may not be possible, or design modifications to the overflow such as a deeper tapered weir design may have to be incorporated. The may also be some flow restriction based on a screen or netting of the overflow entry. I have looked at how flows over weirs and their shape/depths are designed/engineered for open channel flow, but am unsure how these may apply to smaller aquarium systems. Not sure of how the flow would occur or what the consequences might be, should the limited linear inches of overflow be inadequate.
Open to discussion, alternative suggestions or solutions?
I understand one alternative would be to have some of the discharges (e.g. The closed loop circulation lines) drilled into the tank and drawn from the main body of water, but I did wish not to have lines or penetrations in the main tank walls or bottom.
OVERFLOW BOXES:
Here is a link to the tank dimensions. http://www.projectmorpheus.me/CreatureMorpheus/570g_Tank_Specs_%26_Dimensions.html
As mentioned above, I am limited to 50” of coast to coast overflows, which by Reef Central's calculator has a recommended overflow of 3,300 gph. Where as the exiting target flow to the filtration system is approximately 2,400 gph plus an additional closed loop circulation of 3,600 gph. The potential maximum flows could be as much as 3,600 gph to the filtration system and additionally possibly up to 5,600 gph of closed loop circulation.
The display tank has an overall design of 34” high and has a 1.625” laminated bottom and 3/4” glass top reinforcement. The planned top edge to the external overflow boxes is 1.75” down from the top (which would maintain a 3/4” of height (gap) below the top perimeter reinforcement). Expectations of the water flowing over into the overflow boxes would be 1/4” to 3/8” of an inch, an expected maximum 1/2” (would this assumption be accurate?). In reading the recent post, some have had 1” flowing over the weirs of the overflow boxes.
As I am inexperienced and unfamiliar with tank overflow dynamics, I was hoping some people may have knowledge and experience to draw upon and confirm, indicate potential errors or situations, or provide insight or suggestions on where or who I could further investigate matters. Just my logical thoughts regarding the two major segments of “re-circulation” (that flow actual “leaving” the tank by gravity and going to the filtration system) and the closed loop “circulation” - where the water does not “leave” the system or change its water surface elevation. The water being “returned” to the tank from the filtration by pump could potentially have a greater effect on the water surface elevation. Hence, my thoughts were to keep the “circulation” discharges submerged (lower about 1” of the surface) and in a separate external overflow box, rather than the overflow box containing the main exiting discharges to the filtration system. The one downfall to this I see if one of the circulation lines leaks or is compromised, it could potentially lower the water level to below the primary overflow box (containing the re-circulation lines to the filtration). One thought was to keep the second overflow box (containing the circulation pipes) at an elevation 1/4” higher, in that way if there was an issue, and the level dropped because of the circulation lines, the main supply/returns would not be starved.
A main objective was not to have holes within the main display tank and the discharges to occur from only the external overflow boxes. However, based on the potential discharged flow and the 50” of limited inches of overflow, this objective may not be possible, or design modifications to the overflow such as a deeper tapered weir design may have to be incorporated. The may also be some flow restriction based on a screen or netting of the overflow entry. I have looked at how flows over weirs and their shape/depths are designed/engineered for open channel flow, but am unsure how these may apply to smaller aquarium systems. Not sure of how the flow would occur or what the consequences might be, should the limited linear inches of overflow be inadequate.
Open to discussion, alternative suggestions or solutions?
I understand one alternative would be to have some of the discharges (e.g. The closed loop circulation lines) drilled into the tank and drawn from the main body of water, but I did wish not to have lines or penetrations in the main tank walls or bottom.
jason2459
Well-known member
Thanks. So, 2" down to 1" pipe for emergancy and then drill two 1.5" bulk heads to to 1" pvc runs for the full syphon and open channel.
Sent from my DROIDX using Tapatalk
BeanAnimal
Premium Member
@jason
The 2" pipe could be used as a closed loop intake for a large CL pump. If that is not something you wish to do, then it can be used as anything you like, but would best serve as the open channel or emergency. Then (as you have already acknowledged) you would need to drill two more holes for the remaining standpipes.
@creativeguy
I just skimmed your plans, but it appears that you are making things much more complicated than they need be. I will peruse the plans tomorrow when I get a chance and respond with specific thoughts where I can.
Please condider something before we get into much more detail though, you have two isolated weirs that water will flow into. You have no way of ensuring that the flow ratio to each box is maintained. This can (and in most cases will) result in a system that is hard (if not impossible) to keep in balance.
Secondly, while feeding a closed loop from an overflow box is possible and in theory should balance, it increases flow over the weir and can complicate things. In other words, the complications can result in (again) a system that is hard to keep balanced.
More later....
The 2" pipe could be used as a closed loop intake for a large CL pump. If that is not something you wish to do, then it can be used as anything you like, but would best serve as the open channel or emergency. Then (as you have already acknowledged) you would need to drill two more holes for the remaining standpipes.
@creativeguy
I just skimmed your plans, but it appears that you are making things much more complicated than they need be. I will peruse the plans tomorrow when I get a chance and respond with specific thoughts where I can.
Please condider something before we get into much more detail though, you have two isolated weirs that water will flow into. You have no way of ensuring that the flow ratio to each box is maintained. This can (and in most cases will) result in a system that is hard (if not impossible) to keep in balance.
Secondly, while feeding a closed loop from an overflow box is possible and in theory should balance, it increases flow over the weir and can complicate things. In other words, the complications can result in (again) a system that is hard to keep balanced.
More later....
CreativeGuy
Creature Morpheus ...
@ Bean,
Logic or Purpose of the Designed Plumbing:
Please understand the system is designed with two main circulation pumps for redundancy protection to maintain flow and filtration to the tank if one breaks down, is out of commission and takes time to service. As there are two main filtration subsystems (the Skimmer and ATS), and the supply water comes from the two main tank assemblies, the water mixes in collection sumps (approximately 50/50) and are split proportionately as necessary to each filtration branch from there. Again, for redundant protection if I have to service or there is a breakdown to the filtration components or subsystem, any part/component/subsystem is being plumbed with true union ball valves and/or union 3-way valves with by-passes to continue flow through the system and the to the tanks while the components are being serviced or are down.
Overflow Box Access:
The location of the main Display tank limits my access and ability to get to the rear overflow boxes, particularly on the west rear side because of established wall sections and cabinetry. Therefore, can only service the most westerly (left) three discharges from above (on a structural framework as part of the hood) or below the tank (through a cabinet underneath). The remainder of overflow boxes are accessible in a small chase or closet area from the rear. The overflow box at the rear right is shortened or steps up to accommodate one of the two Vortech MP60 pump for optimal location and sufficient surrounding space for water flow (which does not allow me to utilize the last 6 inches or so of the bottom of the overflow box.
Complicated Dynamic Flow Purpose:
Within the tank, the multiple circuits and distributing piping is to be very flexible and adaptable for future rock scape and reef conditions. Its purpose to be able to generate quality flow dynamics that are programable throughout the day. As I do not have a final rock scape or coral/reef plan that will likely continue to change over the years, creating a versatile system I believe is necessary.
Splitting the Boxes and Balancing (referencing your "second" point):
I agree with your comment and have debated whether to separate the two overflows or not. My intent was to try and keep most of the closed loop circuits drawing out from one box and the pump from another. There are pros and cons to doing that, as well as trying to maintain balancing the system. It is my proposed intention at the moment to install in-line union gate valves on ALL the display tank pipes (above on the main floor) to be able adjust the balancing of the system. At present I am trying to find appropriate DC pumps for each circuit and controllers to also tweak and balance things. It is ambitious to do so, but I feel worth the long term effort to try and incorporate.
Logic or Purpose of the Designed Plumbing:
Please understand the system is designed with two main circulation pumps for redundancy protection to maintain flow and filtration to the tank if one breaks down, is out of commission and takes time to service. As there are two main filtration subsystems (the Skimmer and ATS), and the supply water comes from the two main tank assemblies, the water mixes in collection sumps (approximately 50/50) and are split proportionately as necessary to each filtration branch from there. Again, for redundant protection if I have to service or there is a breakdown to the filtration components or subsystem, any part/component/subsystem is being plumbed with true union ball valves and/or union 3-way valves with by-passes to continue flow through the system and the to the tanks while the components are being serviced or are down.
Overflow Box Access:
The location of the main Display tank limits my access and ability to get to the rear overflow boxes, particularly on the west rear side because of established wall sections and cabinetry. Therefore, can only service the most westerly (left) three discharges from above (on a structural framework as part of the hood) or below the tank (through a cabinet underneath). The remainder of overflow boxes are accessible in a small chase or closet area from the rear. The overflow box at the rear right is shortened or steps up to accommodate one of the two Vortech MP60 pump for optimal location and sufficient surrounding space for water flow (which does not allow me to utilize the last 6 inches or so of the bottom of the overflow box.
Complicated Dynamic Flow Purpose:
Within the tank, the multiple circuits and distributing piping is to be very flexible and adaptable for future rock scape and reef conditions. Its purpose to be able to generate quality flow dynamics that are programable throughout the day. As I do not have a final rock scape or coral/reef plan that will likely continue to change over the years, creating a versatile system I believe is necessary.
Splitting the Boxes and Balancing (referencing your "second" point):
I agree with your comment and have debated whether to separate the two overflows or not. My intent was to try and keep most of the closed loop circuits drawing out from one box and the pump from another. There are pros and cons to doing that, as well as trying to maintain balancing the system. It is my proposed intention at the moment to install in-line union gate valves on ALL the display tank pipes (above on the main floor) to be able adjust the balancing of the system. At present I am trying to find appropriate DC pumps for each circuit and controllers to also tweak and balance things. It is ambitious to do so, but I feel worth the long term effort to try and incorporate.
BeanAnimal
Premium Member
Again, I think you are overly complicating the system, if not the explanation of how it works. No worries, we will get it sorted out.
Lets ignore the "length" of the overflows, as that really has no bearing on the fluid mechanics that will dictate if the system balances or not. Lets also ignore flow rates and just concentrate on flow patterns. The response to your "new" explanation will be in a seperate post.
I took the liberty of editing your posts (even some of your wording and sentances) and removing the uneeded information: I have done so in order to simplify the explanation without changing the meaning.
Lets ignore the "length" of the overflows, as that really has no bearing on the fluid mechanics that will dictate if the system balances or not. Lets also ignore flow rates and just concentrate on flow patterns. The response to your "new" explanation will be in a seperate post.
I took the liberty of editing your posts (even some of your wording and sentances) and removing the uneeded information: I have done so in order to simplify the explanation without changing the meaning.
BeanAnimal
Premium Member
When you explain a system or process, choose your words carefully to convey the point with as few words as possible. You have spent a lot of time explaining and quantifying things when brief explanations would suffice and it makes it hard to follow along. We will get to all the little details in time, but lets keep the questions and answers as simple as possible so that the actual points make clear sense. That is, we can't discuss dimensions and flow rates until the basic design methodology and mechanics are sound.
[/quote]One thought was to keep the second overflow box with the closed loop intakes at an elevation 1/4” higher.
My thoughts were to keep the “circulation” discharges submerged (lower about 1” of the surface) and in a separate external overflow box.[/quote] As mentioned earlier, there is simply no way to ensure that TWO separate overflow boxes with weirs at the same height will receive the same proportion of flow at all times. There are far too many variables at play and the system will be hard to keep in balance.
Further complicating the issue is the fact that your pumps will be variable speed and the flow will change constantly. With a shallow weir crest (what we want for surface skimming and to keep fish out of the overflow) the crest height will change as the surge flow is pushed into the tank as the pumps ramp up and down.
The fix is to lower the weir height for the closed loop pumps to the point where the weir does not create a resistance to flow and the ramping up and down of the closed loops does not affect the water level in the tank. At this point the weir will be several inches below the water surface and need to be screened to prevent fish from entering.
In other words, the "closed loop" weir has to be low enough to NOT interact with the weir feeding the sump standpipes.
You still only need (3) standpipes, they will be sized to accommodate the maximum flow created by the (2) return pumps but each still has to function per the design specification. You can't "dedicate" a standpipe to a return pump, as the standpipe has no clue what pump the water is coming from.
Additional "open" channel or siphon pipes can be added if plumbing diameter is a limitation, but increasing plumbing diameter is usually the best option.
That said, I surely would not want my sump in a crawlspace, especially for a 500G system. I spend MOST of my time in the sump area of my system doing maintenance.
You really need to consider the system design with regard to this aspect and consider a MUCH SMALLER below tank sump with nothing (or maybe only the closed loop pumps) in the crawl space.
The standpipe design is what keeps the display tank from ever flooding. You want the "emergency drain to sewer" placed at the absolute high water mark of the sump. In that way a stuck ato or other flood condition during a power outage will prevent the SUMP from flooding, as that is where any "extra" water in the system will end up in a powered or un-powered state. Remember, the overflow system and weir height dictate the maximum water level in the display. The total system water volume dictates the water level in the sump.
As you can see, what happens in the sump or the rate of flow through each piece of the system is not important, nor are the actual dimensions or sizes at this point. A closed loop is a closed loop, its purpose is not really relevant to the basic system mechanics and a sump is a sump. We need to worry about the OM or the ATS, heaters or other equipment yet se we can safely ignore them. That is, if you have questions, keep them to the mechanics and design methodology and we can talk about flow RATES later and plumbing sizes later.
This in itself is perfectly acceptable. However (as mentioned above) feeding the closed loops from the overflow boxes presents some very real challenges, especially if their flow rate is dynamic.
[/quote]One thought was to keep the second overflow box with the closed loop intakes at an elevation 1/4” higher.
My thoughts were to keep the “circulation” discharges submerged (lower about 1” of the surface) and in a separate external overflow box.[/quote] As mentioned earlier, there is simply no way to ensure that TWO separate overflow boxes with weirs at the same height will receive the same proportion of flow at all times. There are far too many variables at play and the system will be hard to keep in balance.
Further complicating the issue is the fact that your pumps will be variable speed and the flow will change constantly. With a shallow weir crest (what we want for surface skimming and to keep fish out of the overflow) the crest height will change as the surge flow is pushed into the tank as the pumps ramp up and down.
The fix is to lower the weir height for the closed loop pumps to the point where the weir does not create a resistance to flow and the ramping up and down of the closed loops does not affect the water level in the tank. At this point the weir will be several inches below the water surface and need to be screened to prevent fish from entering.
In other words, the "closed loop" weir has to be low enough to NOT interact with the weir feeding the sump standpipes.
There is no problem running two return pumps. However, the number of return pumps is not directly tied to the number of standpipes that comprise my silent and fail-safe overflow system.
You still only need (3) standpipes, they will be sized to accommodate the maximum flow created by the (2) return pumps but each still has to function per the design specification. You can't "dedicate" a standpipe to a return pump, as the standpipe has no clue what pump the water is coming from.
Additional "open" channel or siphon pipes can be added if plumbing diameter is a limitation, but increasing plumbing diameter is usually the best option.
This presents several problems and can create an air-lock if not well designed. You may also have some issue with getting the open channel to stay quite (depending on configuration). No matter what, the balancing valve for the siphon is going to need to be at the end near the sump.
That said, I surely would not want my sump in a crawlspace, especially for a 500G system. I spend MOST of my time in the sump area of my system doing maintenance.
You really need to consider the system design with regard to this aspect and consider a MUCH SMALLER below tank sump with nothing (or maybe only the closed loop pumps) in the crawl space.
Certainly fine, but (as mentioned above) you need to reconsider the intakes.
Wrong place
The standpipe design is what keeps the display tank from ever flooding. You want the "emergency drain to sewer" placed at the absolute high water mark of the sump. In that way a stuck ato or other flood condition during a power outage will prevent the SUMP from flooding, as that is where any "extra" water in the system will end up in a powered or un-powered state. Remember, the overflow system and weir height dictate the maximum water level in the display. The total system water volume dictates the water level in the sump.
As you can see, what happens in the sump or the rate of flow through each piece of the system is not important, nor are the actual dimensions or sizes at this point. A closed loop is a closed loop, its purpose is not really relevant to the basic system mechanics and a sump is a sump. We need to worry about the OM or the ATS, heaters or other equipment yet se we can safely ignore them. That is, if you have questions, keep them to the mechanics and design methodology and we can talk about flow RATES later and plumbing sizes later.
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RocketSurgeon
New member
I didn't miss your question, I just don't know the answer.
BeanAnimal
Premium Member
@RAM1500 If you google NPT tap drill size, you will find numerous tap drill size references.
In most cases, you can use the closest "normal size drill you have and get a good seal with teflon thread tape or paste. The JG fitting will be NPT pipe thread, so finding the size should not be that hard. It is likely either 3/8" or 1/2" NPT
In most cases, you can use the closest "normal size drill you have and get a good seal with teflon thread tape or paste. The JG fitting will be NPT pipe thread, so finding the size should not be that hard. It is likely either 3/8" or 1/2" NPT
CreativeGuy
Creature Morpheus ...
@Bean:
Sorry for the length, will try to be more concise.
Overflows and Stand Pipes in Main Tank:
As for the overflow protection being in the wrong place, I thought it appropriate to have one in the main tank as well, but it seems you think it is unnecessary because the (3) standpipes to the sump do the same thing. Having the (3) standpipes was matched to have sufficient “total” flow accommodation to the collection sumps below, not expected to be matched a specific pump. Also that if I took one line off line for service, cleaning or repair, there would be sufficient capacity to maintain the filtration.
Over-sizing the Open Flow Standpipe: If I understand you correctly, you mentioned or suggested possibly over-sizing the “open” channel pipe size, possibly going to 2” instead of the 1.5”, which should not be a problem at this stage. This may help with noise. The two main siphon flow standpipes would remain at 1.5”.
Placement of the Gate Valves for Balancing: My thoughts were to place the gate valves above the floor so I could see what was happening when balancing and adjusting. However, if the gate valve location is best at the end of the siphon near the sump, it can easily be done.
Interior Dimension of the Overflow Box and Bulkhead Fitting Size: The interior overflow box dimension is only 4.5”, which may have to be bigger to accommodate a 2” bulk head fitting, or alternatively go out the lower back plate of the overflow box horizontally for that pipe with 90d elbows and internal standpipe. Doing a combination of bottom and rear entries into the overflow box may be easier to plumb as well.
Over-flooding Protection in Sumps: The main sumps in the crawl space also were designed for “normal operating level” and “capacity for drain down” and at the highest point an overflow drain to the home's sewer for flood protection.
Location and Separation of the Closed Loop Circuits: I can see about changing the locations for all the closed loops into a separate sump such that the weir level is lowered as you suggested and independent of the discharge out of the tank and their overflow box. Also the thoughts for the closed loop standpipes was to be 4” to 5” minimum below the surface (and use strainers) as not to draw air or create swirling vortexes, would this not be wise?
Balancing: Would agree with you about the varying fluctuations caused by the changing flows, is expected and will be a challenge to balance and accommodate.
Air-Locks: The piping follows the typical standards and requirements for plumbing such as minimum of 1/4” per foot fall and fitting installation in a manner not to cause traps. Am I missing something or are you suggesting because of the length of run, or configuration of the silent flow fittings, somehow was cause air trapping to occur?
Location in Crawl Space: As for the location of the sumps and filtration equipment being located in the crawl-space, I have no choice. There is very limited basement area (less than 250 sq. ft) and beneath the tank on the main floor is not an option. I do not look forward to maintaining the filtration system in the crawl space, I know, but otherwise could not do the project.
Sorry for the length, will try to be more concise.
Overflows and Stand Pipes in Main Tank:
As for the overflow protection being in the wrong place, I thought it appropriate to have one in the main tank as well, but it seems you think it is unnecessary because the (3) standpipes to the sump do the same thing. Having the (3) standpipes was matched to have sufficient “total” flow accommodation to the collection sumps below, not expected to be matched a specific pump. Also that if I took one line off line for service, cleaning or repair, there would be sufficient capacity to maintain the filtration.
Over-sizing the Open Flow Standpipe: If I understand you correctly, you mentioned or suggested possibly over-sizing the “open” channel pipe size, possibly going to 2” instead of the 1.5”, which should not be a problem at this stage. This may help with noise. The two main siphon flow standpipes would remain at 1.5”.
Placement of the Gate Valves for Balancing: My thoughts were to place the gate valves above the floor so I could see what was happening when balancing and adjusting. However, if the gate valve location is best at the end of the siphon near the sump, it can easily be done.
Interior Dimension of the Overflow Box and Bulkhead Fitting Size: The interior overflow box dimension is only 4.5”, which may have to be bigger to accommodate a 2” bulk head fitting, or alternatively go out the lower back plate of the overflow box horizontally for that pipe with 90d elbows and internal standpipe. Doing a combination of bottom and rear entries into the overflow box may be easier to plumb as well.
Over-flooding Protection in Sumps: The main sumps in the crawl space also were designed for “normal operating level” and “capacity for drain down” and at the highest point an overflow drain to the home's sewer for flood protection.
Location and Separation of the Closed Loop Circuits: I can see about changing the locations for all the closed loops into a separate sump such that the weir level is lowered as you suggested and independent of the discharge out of the tank and their overflow box. Also the thoughts for the closed loop standpipes was to be 4” to 5” minimum below the surface (and use strainers) as not to draw air or create swirling vortexes, would this not be wise?
Balancing: Would agree with you about the varying fluctuations caused by the changing flows, is expected and will be a challenge to balance and accommodate.
Air-Locks: The piping follows the typical standards and requirements for plumbing such as minimum of 1/4” per foot fall and fitting installation in a manner not to cause traps. Am I missing something or are you suggesting because of the length of run, or configuration of the silent flow fittings, somehow was cause air trapping to occur?
Location in Crawl Space: As for the location of the sumps and filtration equipment being located in the crawl-space, I have no choice. There is very limited basement area (less than 250 sq. ft) and beneath the tank on the main floor is not an option. I do not look forward to maintaining the filtration system in the crawl space, I know, but otherwise could not do the project.
BeanAnimal
Premium Member
Lets ignore the number of standpipes for a moment.
The system needs (3) types of flow.
1) Siphon
2) Open Channel
3) Dry (not flow, but you get the point)
Each type or mode of flow can be accomodated by 1 or more physical standpipes, but each type must be present for the system to operate as designed and expected.
Taking a return pump offline will alter the balance of the system (in this case causing it to suck air due to the lower flow). While we could try to design around this with standpipes at different levels, it is more trouble than it is worth. You balance the system for the NORMAL operating flow, not maintenance flow.
Depending on plumbing diameter, you should be able to accomodate the entire standpipe setup with (3) standpipes of sufficent diameter to handle your proposed flow, no matter how many return pumps are responsible for creating it.
If you can not accomodate LARGER diameter plumbing, then a second SIPHON can be added. You still need AT LEAST one open channel and the emergency drain (Now you are at 4 standpipes).
With a 7' drop and a 20' run, you will likely have cavitation if the valve is not low enough in the system. At the very least you can try it at floor height, but be prepared to have one at the sump level.
The interior overflow box dimension is only 4.5", which may have to be bigger to accommodate a 2" bulk head fitting, or alternatively go out the lower back plate of the overflow box horizontally for that pipe with 90d elbows and internal standpipe. Doing a combination of bottom and rear entries into the overflow box may be easier to plumb as well./quote] The water could care less where it breaches the tank wall
That is all you need, as long as the standpipes in the display are designed in the manner suggested in this thread. The whole idea is a fail-safe overflow system for the display.
I prefer to TEE the intakes for LARGE closed loops so that larger critters can not partially block the intake and get stuck due to the increased suction that results from the blockage. If your intakes are in an EXTERNAL BOX fed by a screened weir that is several inches deep, then this may not be a problem due to a simple matter of surface area. That is, lets assume that the you cut an 18" wide 6" deep slot for the closed loop box. That is 108 square inches. You have for 2" intakes in the box, or about 12 square inches of intakes. That is a velocity reduction of about 9 times. Much safer than (4) screened 2" intakes.
That said, if you do decide to directly plumb the intakes through the back wall of the tank, then I would put TEEs on them (as mentioned above) and split them into at least (2) strainers per intake.You could pull the intake for the "rock" loop from the top, the intake for the OM from the bottom and the other two intakes from opposite sides of their discharge.
This is not typical plumbing, so most design conventions have no bearing. There will be a huge amount of air trapped in the siphon standpipe that must be purged at each startup. You must also ensure that the open channel does not end up being two phase flow (air and water mixed creating a partial siphon) or it will create a lot of noise.
The horizontal runs for the OPEN CHANNEL and Emergency pipe will need to be much larger than the vertical standpipes (at least a plumbing size) and need to have sweep type bends at the horizontal to vertical transition below the floor. This will allow air to flow in the pipe and prevent two phase flow and splashing. They should not transition back to vertical if it can be helped, as the transition will likely create splashing and noise. You can increase the angle and enter the sump at a 45 if possible.
I don't see wiggle room on this. You are creating a nightmare that is almost beyond comprehension for a tank this size. I would design the system with a sump UNDER the stand. You can place your pumps in the crawlspace (even the return pumps if you need to).
While you may be dedicated enough to crawl into the sump area to do daily maintenance, history and reality show that most folks will quickly grow tired of such an act and the tank will suffer.
BeanAnimal
Premium Member
He is refering to an external overflow box dedicated to CL intakes. For it to work with the variable speed pumps, it needs to be more of a screened off section of the tank, not an overflow box with a shallow weir.
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