Silent and Failsafe Overflow System

[lexzbuddy]

Noisy second line, please help

Noisy second line, please help

I have been trying to set up my bean overflow but it's noisy as hell.

I get the main line to go full syphon and after a couple of minutes, it's totally bubble free and silent. I had to drill a couple of holes just below the surface of the water at the outlet in the sump to ensure that the air was purged to allow the syphon to form, (I read about that earlier in this thread and it worked).

The secondary line has a hole in the cap with a 6mm Pneumatic fitting and hose to prevent it from going full syphon. It is above the water when the primary is in full syphon so air can get in. This line is making a huge amount of noise and is the problem, (it's the one that is noisy at any rate and I perceive it as he problem).

The emergency overflow is fully open and clear of the water throughout. Obviously not an issue.


If I open the primary fully, it manages to keep up with my return pump on its own and will eventually overtake it and the syphon will break. It will keep doing this until I close the valve to restrict it a bit.

I have tried varying the main syphon's flow rate with its valve to try to mitigate the noise being produced by the secondary line. Small incremental changes to see if there was a sweet spot.

I have tried fully closing the secondary and letting the emergency line take over with the excess. This results in a slight trickle going down and you can hear it trickling into the sump from the open end. It has no problem taking up the slack but it is a little noisy as one would expect, being open to the atmosphere and all.

When I crack open the secondary, it starts all over again. There's a slug of water behind the closed valve, upon opening it fires through to the sump then you get gurgling, bubbling noises coming from the line. Bubbles come out of the line continuously when entering the sump. The hose outlet is below the water so it isn't splashing about, just in case anyone may have thought it was that.
I have tried to incrementally vary it's position but it doesn't seem to help.

Do you think drilling a couple of small holes in the outlet of the secondary as per my primary may help?

I'm a bit stumped at this point. Any help greatly appreciated.


I have used 28mm pipework throughout.
Swept Tees with threaded caps at the inlet, (hoping they would be less turbulent) :facepalm:
My return is a DC 4000 liter/hour pump, variable speed.
Top of tank is about 5 feet to weir inlet.

 

[Ted_C]

The secondary line has a hole in the cap with a 6mm Pneumatic fitting and hose to prevent it from going full syphon. It is above the water when the primary is in full syphon so air can get in. This line is making a huge amount of noise and is the problem, (it's the one that is noisy at any rate and I perceive it as he problem).

Is it the noise of the air going through the tube or the water in the pipe that's causing your complaint?

Noise of the air through the tube: get a bigger airline (mine's 3/8" - nearly 10mm). Or - maybe you engage the airtube in your open channel (during startup) before you engage the emergency drain? The emergency drain should be triggering before the airline tube triggers.

Water in the pipe - divert more water through your siphon. Open up the siphon a bit more or raise the inlet for the open channel a little bit.

 

[lexzbuddy]

Thanks Ted, I shall have a go at that.

The noise is coming from air mixing with water in the open channel.

Raising the open channel will be difficult but, I suppose needs must. I will need to do a bit of cutting of pipework. Ho hum, such is life.

Again, many thanks for your help, greatly appreciated.

 

[uncleof6]

I have been trying to set up my bean overflow but it's noisy as hell.

I get the main line to go full syphon and after a couple of minutes, it's totally bubble free and silent. I had to drill a couple of holes just below the surface of the water at the outlet in the sump to ensure that the air was purged to allow the syphon to form, (I read about that earlier in this thread and it worked).

Should not be necessary to drill holes in the siphon in order to get the air to purge. A system that follows the basic design principles of the BA system, does not require such modifications. Only systems that do not follow the basic design principles require band aids to get them to function.

The secondary line has a hole in the cap with a 6mm Pneumatic fitting and hose to prevent it from going full syphon. It is above the water when the primary is in full syphon so air can get in. This line is making a huge amount of noise and is the problem, (it's the one that is noisy at any rate and I perceive it as he problem).

This description is a bit "obfuscated." To be clear, the inlet to the air vent line should NEVER be under water at any time, unless both the siphon and dry emergency have failed. This includes during startup. The inlet to the air vent line should be higher than the inlet to the dry emergency. There is no relation to the siphon.

The emergency overflow is fully open and clear of the water throughout. Obviously not an issue.

Ok. However, is the inlet to the dry emergency high enough to develop enough "start head pressure" in the overflow box to fully purge the air out of the siphon during startup? Water should rise, and flow in the dry emergency during startup, and when the air is purged from the siphon, the water level drops. If this does not occur, or the open channel takes the flow instead of the dry emergency, the system is not starting right, and adjusting the system for proper operation can be frustrating.

If I open the primary fully, it manages to keep up with my return pump on its own and will eventually overtake it and the syphon will break. It will keep doing this until I close the valve to restrict it a bit.

I have tried varying the main syphon's flow rate with its valve to try to mitigate the noise being produced by the secondary line. Small incremental changes to see if there was a sweet spot.

I have tried fully closing the secondary and letting the emergency line take over with the excess. This results in a slight trickle going down and you can hear it trickling into the sump from the open end. It has no problem taking up the slack but it is a little noisy as one would expect, being open to the atmosphere and all.

When I crack open the secondary, it starts all over again. There's a slug of water behind the closed valve, upon opening it fires through to the sump then you get gurgling, bubbling noises coming from the line. Bubbles come out of the line continuously when entering the sump. The hose outlet is below the water so it isn't splashing about, just in case anyone may have thought it was that.
I have tried to incrementally vary it's position but it doesn't seem to help.

Do you think drilling a couple of small holes in the outlet of the secondary as per my primary may help?

I'm a bit stumped at this point. Any help greatly appreciated.

All symptoms of systems that fall outside the basic design principles of the BA system.

My question is, what is not done according to the basic design principles with your system? Most all problems are solved with this system by following the basic design principles that were not followed in the first place.

I have used 28mm pipework throughout.
Swept Tees with threaded caps at the inlet, (hoping they would be less turbulent) :facepalm:
My return is a DC 4000 liter/hour pump, variable speed.
Top of tank is about 5 feet to weir inlet.

But what is the actual drop height or "head height" from surface of water in the overflow, and surface of water in the sump? And what is the head height from the surface of water in the tank, to the surface of the water in the sump. These are the numbers that have relevance. Affects the drain capacity, but not necessarily how high the water level in the overflow box needs to rise to purge the air in the siphon, but it can.

Part of your problem is the size of the plumbing you are using for the open channel. 28mm (not any better than 25mm; e.g. ~1" and 1.1", is too small for a practical quiet Durso. The smallest practical size is 1.25" (~ 30mm. 31.something to be closer,) It is very difficult, to keep a Durso this small quiet.

Also, increasing the amount of air in the standpipe (e.g. increasing the size of the air vent line or increasing the hole size,) will not solve the problem. This allows more air into the line, meaning that less water can be in the line and have it still be quiet. The standpipe has to be < 1/4 full of water, or it is in turbulent flow, (air and water mixing.) This is what creates the noise.

 

[BlueRoofTang]

If you have three separate drains, think this through by process of elimination...and lets look at facts:

The siphon line isn't making noise when it's full and siphoning...because there is no air in the line.

The open channel is making noise because it has water and air in it.
-Water displaces air, which can then move and make noise.
-Water moving can make noise when air is present.

So the problem lies in that... you have too much water flowing into the open channel line. It then means noise from water moving and/or noise from the air being displaced by the water.

The fix: Less water in the open channel line. You probably need to open the valve in the siphon line just slightly.

If that's not it, your problem may be in the height of the elbows, as mentioned above.

 

[rwgarrison]

75 Gallon Tank Project

75 Gallon Tank Project

I'm brand new to the saltwater reef hobby. I have had a couple different freshwater tanks through the years - but that is it. I was given a 75 Gallon Tank with stand so now I've been reading and reading and reading. The tank came with 2 drains through the back and the return was an over the top.

I have decided to remove the plumbing and drill 2 more holes so I can put in a Silent and Failsafe Overflow System (using an internal overflow box) reusing one of the existing holes. I plan on using the second existing hole for the return, probably using loc-line. Here is the back of the tank with the plumbing removed:

Below is a drawing I put together that shows where I plan to drill the new holes and it also shows the outline of the overflow box. I'm planning on making the overflow box 3 inches deep (not shown). It is not coast to coast due to the other already existing hole.

Looking for confirmation that I'm approaching this correctly and if not, what should I be doing differently. I understand that I still need to specify the plumbing itself, and will do that as I move forward. Thanks.

Ron

 

[rwgarrison]

As I think about this further... Would I be better off doing a narrow coast to coast internally and mount an external overflow box around the two existing holes and put the piping there? Will the uneven existing holes cause me problems as the water flows to the external box? Then stay with an over the top return. Thanks.

Ron

 

[BlueRoofTang]

I don't know what the previous owner of that tank was thinking... really odd placement of holes.

The problem is that you can't really use the lower one for a good drain, and if you use it as a return, it will siphon a lot of the water out of the tank in the event of a power failure.

I would suggest two options:

1) Put an elbow inside the tank, upwards, or some loc-line near the water surface. This will effectively put your return up higher and help with siphoning in a power outage.

2) Put a bulkhead and a plug in the lower one. Then you can drill your return wherever you want it.

As far as the drain, try to use one of the higher of the holes for one of the three required for a Synergy Ghost.

 

[rwgarrison]

Thanks for the feedback - yes that is what I originally was thinking of doing. Use the upper of 2 holes as 1 of my 3 for the drain. And use the lower hole for the return with a loc line up to the surface to minimize siphon issues in the event of a power loss.

Now another question. What if I did this instead. Instead of using an internal overflow I use an external overflow.

So - I would install a coast to coast box for skimming - maybe inch or inch and a half from the rear glass and deep enough to encompass both existing holes. This would provide skimming and the water would flow out the two existing holes into an external box wide enough to cover both holes. I would have 3 holes in the bottom of the external box for the drain pipes. This approach would require no more drilling on the tank itself.

For the return - I would probably just go over the top.

Would the offset of the existing holes cause issues in the water flow to the rear overflow box?

Ron

 

[uncleof6]

Thanks for the feedback - yes that is what I originally was thinking of doing. Use the upper of 2 holes as 1 of my 3 for the drain. And use the lower hole for the return with a loc line up to the surface to minimize siphon issues in the event of a power loss.

Now another question. What if I did this instead. Instead of using an internal overflow I use an external overflow.

So - I would install a coast to coast box for skimming - maybe inch or inch and a half from the rear glass and deep enough to encompass both existing holes. This would provide skimming and the water would flow out the two existing holes into an external box wide enough to cover both holes. I would have 3 holes in the bottom of the external box for the drain pipes. This approach would require no more drilling on the tank itself.

For the return - I would probably just go over the top.

Would the offset of the existing holes cause issues in the water flow to the rear overflow box?

Ron

I worked with pass through holes around 9 or so years ago... not worth the effort. The last system I built using the pass-through concept worked, (and adhered to the basic design principles of the BA system) but really was not worth the extra effort involved. (building an external box.) The subsequent "fad" or "race" to stuff Bean's system into the smallest box possible is fraught with issues, as shown by the required modifications to get the Synergy overflow to work at all. It still does not adhere to the design principles of BA's system, and does not really work the same. This makes trouble shooting a matter of fixing what does not adhere to the basic design principles.

By leaps and bounds, your original idea in your first post is the better idea, than subsequently suggested following. Run the return over the top, (the best performing return) and plug the oddball hole (with a plugged bulkhead.) You can pretty much be assured that it will work out of the box, without having to mess with it.

 

[Lsufan]

If u want to go with a c2c box then u can use the lower hole as the emergency drain, so it will have a elbow facing up. It doesn't look to be but about 1" below the other hole, so if u use it as the emergency u probably won't even have to make the box any deeper then normal to accommodate it.
I don't think I would use it for a return because u would have to rely on locline to not have a bunch of water drain down when it's powered off. If the locline gets pushed down for some reason it may cause u to have a flood. If u have a really big sump with a lot of extra room then it may not matter.

U can eighther go a full c2c & use it as the emergency & go over the back with the return or u can go with the internal wier & exterior box & use it as one of the pass through holes. I know uncle isn't a fan of that setup & he is more knowledgeable then I am, but I like the synergy style boxes. I just don't like the sizes they make them in. I like to have as long of a wier as possible on the inside of the tank & a bigger exterior box then what they make. One of the things I like about this setup other then the space I save is u can use black acrylic for the internal box & have the bulkheads hold it on the tank, Then do a glass exterior box. I really like the look of the black acrylic. I don't know if it would be worth the extra work just to save 1.5" in the tank, but I wanted a acrylic box so between the two it was worth it to me.

As far as the returns, if u don't want to go over the back of the tank then from the looks of it u have enough room between the edge of the tank & the existing holes to drill another hole for your returns. If u did it this way then u could have a longer internal box. U can make the internal box to where it covers your existing holes & still have room for returns on the ends as long as u have around 6" from the edge of the tank to where your existing hole starts.

 

[rwgarrison]

Thank-you for your responses. All very helpful. #1 thing learned, do not use the existing lower hole for return. Just asking for trouble.

I'm leaning towards going with an internal box. Question about your acrylic wier though for your external design. Don't you still have to make sure there are no leaks in the internal weir (otherwise the tank would drain to the level of the lowest leak higher than your holes with a power loss, wouldn't it?)? If so, how would you guarantee that with acrylic?

Question on hole size. The current hole size is 2" diameter and they had schedule 40 1" bulkheads installed. 2" seems big to me for that but seems to have worked before. Am I asking for trouble if I continue to use a schedule 40 1" bulkhead? It seems like the only other option would be to move to schedule 80 1", but that seems like overkill. I'm assuming if I drill 2 more holes I can make them smaller and put the same size bulkheads in.

BTW I'm using a 20 Gallon fishtank for the sump. So I don't have huge overflow space there but with the proper design I believe it should be enough.

Thanks again,

Ron

 

[pweissma]

Running a manifold off the siphon

Running a manifold off the siphon

I have a 60g cube with an overflow box from Exotic Marine Systems. It's similar to the Ghost overflow. I reduce the siphon to 3/4" and the open channel and emergency at 1". My sump is high on a shelf in my basement giving about 7 feet drop from the water surface. Siphon starts quickly, reliably and without any trouble. It takes less than a minute. Water fills to the emergency drain. After about the 10 seconds the siphon starts and pulls water down below the open channel. Then the water gradually rises back up to the open channel.

I'm considering putting a manifold on the siphon to run two Avast Marine reactors, a small spyglass reactor with very minimal flow and one of their small sized standard regular reactors running biopellets. The flow through the biopellets needs to be a bit more substantial.

I'm wondering if the manifold will create problems for system startup. All help is greatly appreciated! Thanks.

 

[uncleof6]

I have a 60g cube with an overflow box from Exotic Marine Systems. It's similar to the Ghost overflow. I reduce the siphon to 3/4" and the open channel and emergency at 1". My sump is high on a shelf in my basement giving about 7 feet drop from the water surface. Siphon starts quickly, reliably and without any trouble. It takes less than a minute. Water fills to the emergency drain. After about the 10 seconds the siphon starts and pulls water down below the open channel. Then the water gradually rises back up to the open channel.

I'm considering putting a manifold on the siphon to run two Avast Marine reactors, a small spyglass reactor with very minimal flow and one of their small sized standard regular reactors running biopellets. The flow through the biopellets needs to be a bit more substantial.

I'm wondering if the manifold will create problems for system startup. All help is greatly appreciated! Thanks.

Yes it will create problems for the startup. All three standpipes must be discrete, and go directly to the sump. Do not pass go, do not collect $200. If needing to feed "reactors" feed them from a tee in the return line, or run them on a separate pump... or simply eliminate them from the system altogether, considering the choice of reactors you have made.

 

[pweissma]

Yes it will create problems for the startup. All three standpipes must be discrete, and go directly to the sump. Do not pass go, do not collect $200. If needing to feed "reactors" feed them from a tee in the return line, or run them on a separate pump... or simply eliminate them from the system altogether, considering the choice of reactors you have made.

Thanks but you didn't identify any reason why it would create a problem at startup. I'm not merging any of the standpipes. The siphon would be divided into three but all three would go directly into the sump. BTW, I have been running the reactors off Ts from the return.

 

[BlueRoofTang]

It wont. Think about siphoning from a bucket.....you only need yo get it started. The bottom end does not have to be in the water it does make it quieter though.

 

[sleepydoc]

There are several potential problems running the siphon to a manifold running reactors. First, the back pressure caused by the reactors will slow the flow and also not be constant, causing the siphon flow to slowly 'drift' over time. The system can accommodate this to a degree but if you're only using 1" pipes for the open channel and dry emergency you can't put a lot of flow down the open channel before it starts caveating and creating noise.

During startup, the reactors will tend to trap air, which may interfere with the development of the siphon. In addition, if the total resistance is too high, the flow will be too slow to effectively clear the air, preventing the siphon from starting at all. It may work, but you can't depend on it. Keeping it like you have it (tee'd off the return) is a better bet IMO.

 

[pweissma]

There are several potential problems running the siphon to a manifold running reactors. First, the back pressure caused by the reactors will slow the flow and also not be constant, causing the siphon flow to slowly 'drift' over time. The system can accommodate this to a degree but if you're only using 1" pipes for the open channel and dry emergency you can't put a lot of flow down the open channel before it starts caveating and creating noise.

During startup, the reactors will tend to trap air, which may interfere with the development of the siphon. In addition, if the total resistance is too high, the flow will be too slow to effectively clear the air, preventing the siphon from starting at all. It may work, but you can't depend on it. Keeping it like you have it (tee'd off the return) is a better bet IMO.

Thanks. Makes sense. Unlike most on this forum my tank is small (60g) and my sump flow is about 500g so the 1" open channel and emergency do give enough flexibility. The point about 'drift' will exist with the reactors T-ed off the return as the water returning to the tank from the return pump will depend on the back pressure from the reactors. But this is my current setup and it works fine.

I'm not convinced that 'drift' would exist if the reactors were T-ed off the siphon. Siphon flow is a the product of cross section and length this won't change. I suspect that changes in back pressure from the reactors will only change the percentage of water that goes to the reactors vs directly to sump making the system slightly more stable.

I think the whole issue is about siphon startup and, yes, air in the reactors might be a big issue. Wish there was some way to test before re-plumbing.

 

[sleepydoc]

Another thing to remember with your proposed setup is that you likely will get very little flow through the reactors if simply have them tee'd off with an open pipe taking the rest of the flow straight down to the sump there may well be too little pressure to the reactors. The only way to make it work would be to have the tee be above the gate valve.

Drift will absolutely occur. Whether it will be significant enough to be an issue or not is unknown. Siphon flow is a function of gravity, the height drop, fluid density & viscosity and the resistance to flow. The resistance to flow is ideally a function of pipe diameter, but the rate of flow, the fittings, surface resistance, etc also come into play, so saying 'I know the height and pipe diameter, therefore I know the flow' is a bit simplistic. Realistically, the only way to test this is to build it.

 

[rwgarrison]

By leaps and bounds, your original idea in your first post is the better idea, than subsequently suggested following. Run the return over the top, (the best performing return) and plug the oddball hole (with a plugged bulkhead.) You can pretty much be assured that it will work out of the box, without having to mess with it.

Any reason, instead of plugging up the oddball hole, I use it for the emergency with a c2c internal box. I just need to make sure the upturned elbow is even with the top of the overflow box, possibly by adding small piece of pvc, if needed - right? This way I drill one more hole next to the other higher hole and put the main and open there.

And as it is the emergency, It doesn't really matter where it spills into the sump does it? (i.e. I don't have to pipe it way back over to where the other two spill into the sump)

Just want to make sure I'm not missing something. Thanks again.

Ron