Separate Overflow for Closed Loop

[jdarr]

Hey fellow fish nerds..., I wanted to get some feedback on an idea I had regarding a closed loop system...

I am looking to have 2 overflow boxes in my tank. One with the regular height teeth for water to flow over the weir and supply the main drain to the sump. As water gets pumped into the tank, the water level flows over the weir and drains back into the sump through this regular overflow box... (yeah, pretty straight forward so far)

But then, I want to have another overflow box, same physical height as the other, except the teeth are cut a little lower which supplies the closed loop pump/system... The way I understand this, even if the main sump pump is off and no more water is being pumped back into the tank, the lower teeth in this box should still be low enough to supply the closed loop with enough water... right? It would certainly be a lot cleaner looking than huge strainers (and safer for critters?)

I am not sure if anyone else has tried this, but I wanted to get some feedback before I have my tank built like this as I think this should work... I will post a rendering shortly

Any input would be welcome!

Thanks guys!

 

[jdarr]

image below (first time using photo bucket so I hope it works)
http://i1109.photobucket.com/albums/h429/jpdarr/overflowwithclosedloopintake.jpg

So if you are looking at the image, you can see the overflow is divided into two separate overflows.
from left to right is as follows:

Main return line
oceans motions A return 1
oceans motions A return 2
oceans motions A return 3
oceans motions A return 4
Closed loop 1 feed line
Closed loop 2 feed line
***divider
oceans motions B return 1
oceans motions B return 2
oceans motions B return 3
oceans motions B return 4
Main Herbie drain
Back up Herbie drain

 

[Timber77]

cant see your picture but having your closed loop draw water from the top of your tank is fine unless your tank level drops below the "teeth" on this pump intake wier. In that case you run your pump dry and most aquarium pumps are not designed to run dry. Thats the downside.... so make wier for the closed loop significantly lower than wier to the sump and you will be all good. (im assuming whatever a hervie drain is it is some kind of overflow/wier)

curious why you would go with a closed loop in 2013 on a new setup , kinda older technology when the little prop pumps like mp40 wp40 tunze etc out there can move the water and make real waves etc.

 

[jdarr]

cant see your picture but having your closed loop draw water from the top of your tank is fine unless your tank level drops below the "teeth" on this pump intake wier. In that case you run your pump dry and most aquarium pumps are not designed to run dry. Thats the downside.... so make wier for the closed loop significantly lower than wier to the sump and you will be all good. (im assuming whatever a hervie drain is it is some kind of overflow/wier)

curious why you would go with a closed loop in 2013 on a new setup , kinda older technology when the little prop pumps like mp40 wp40 tunze etc out there can move the water and make real waves etc.

Thanks for the input Timber77. Yes, my plan was to have the closed loop overflow teeth lower to prevent the pump from drawing air. I will post images below to try and give the idea more clarity. I was also considering having a couple vertical slits cut into the overflow box and baffle behind it that would force the water to travel up and over the baffle to reach the drain (keeping the tank water level unaffected below the height of that baffle). I'll post some rough renders for this as well:

This is the front view of what I was thinking


and the back view


and the slits/baffle idea (it's rough)


and the other angle to view this idea


Herbie drains are basically a siphon system that allow VERY fast water movement from the overflow to the sump. With one 2 inch drain (and a second for a back up in case of a plug) I would be able to move about 9400 gallons per hour (silently I might add) through that drain into my sump (yes, this is overkill but would rather be able to add flow as needed then not have enough... additionally, a 2 inch pipe is not likely to plug lol;-))

I wanted to go closed loop for the main reason that I don't really like the look of powerheads. I have used Tunze's in the past, and find them very effective, but they are impossible to hide while also allowing for maintenance/replacement (or compromise the quality of your flow). The cabling and controlling is messy and I wanted to go with some effective but simple and easy...

Additionally, I found the life expectancy of powerheads to be relatively short, maintenance is a PITA and as a result have decided to go with closed loop. The only service I expect for my CL is to service a dart pump when needed occasionally which is out of the tank at all times ;-). I plan to use 2 dart, 2 oceans motions and a hammerhead for my main return. (more details when I get closer to starting the actual build)

I have never tried the Vortech pumps, but again, seeing them is the issue for me. I plan on hiding the closed loop return lines behind rock work (ala Stuart Bertram's tank - http://www.youtube.com/watch?v=C30zRuTfcjk&list=PL58D40CE192F0FB0D) and never having to worry about it again. (hopefully:lmao

 

[jdarr]

So, I have been giving this some thought and researching this a bit more (thanks for the nudge Timber77 ;-)) and I am considering ditching the CL for a couple MP 60's. Does anyone run these on a tank this size? Any comments etc? Seems like with the flow rating (7k gallons per hour) would be more than sufficient, but I am curious as to whether or not 2 of these would actually keep detritus in suspension effectively removing dead spots? Any other thoughts?

 

[ca1ore]

I don't think there is anything wrong with running a closed loop if you already have a pump sitting around. If you would have to buy one, then I agree that something like the Vortechs would be better.

 

[jdarr]

I don't think there is anything wrong with running a closed loop if you already have a pump sitting around. If you would have to buy one, then I agree that something like the Vortechs would be better.

If money was no object.... (which of course it always is ;-)), would you do CL or Vortechs?

 

[ca1ore]

Well, I actually do both. I use a closed loop circulation pump to get water movement behind my live rock (which powerheads won't do well) and a pair of Vortech pumps to get surge in the open water column (which a circulation pump won't do well). I do run the suction side of my CL in the overflow, but that overflow also contains a standpipe to regulate water level.

In your diagram, assume you were planning to use the 8-way oceans motion device? Frankly, I'd be a bit concerned about having that many holes in the bottom of the tank. You might be better off with just two CL returns along the bottom of your rockwork and a couple of Vortechs. On a 90 gal, I use one MP40 and one MP10 and it is more than enough. In tank profile is quite minimal which is nice.

 

[jdarr]

Well, I actually do both. I use a closed loop circulation pump to get water movement behind my live rock (which powerheads won't do well) and a pair of Vortech pumps to get surge in the open water column (which a circulation pump won't do well). I do run the suction side of my CL in the overflow, but that overflow also contains a standpipe to regulate water level.

In your diagram, assume you were planning to use the 8-way oceans motion device? Frankly, I'd be a bit concerned about having that many holes in the bottom of the tank. You might be better off with just two CL returns along the bottom of your rockwork and a couple of Vortechs. On a 90 gal, I use one MP40 and one MP10 and it is more than enough. In tank profile is quite minimal which is nice.

Very interesting... I was planning 2 darts and 2 oceans motions 4 way for the CL... And since these drawing were posted I was planning on going over the top rather than drilling so many holes...but, if the vortechs are that great at moving the water column, perhaps I can plumb my main return to hit behind the rocks? I will be using a hammerhead, so perhaps with some creative plumbing with the hammerhead return and a couple of the MP 60s for the bulk of the tank would do the trick? I love the idea of waves that the vortechs create and with the hammerhead washing behind the rocks.... does this sounds like it would be problematic? Obviously I'd need a syphon break etc...

 

[ca1ore]

I'd have to think about the siphon break. I think as long as any standpipe that shares the overflow with the CL suction side is near the top of the tank you will be OK. Under no circumstances should you have the herbie siphon in the same overflow, otherwise in the event of a power loss your tank would drain down to the top of the herbie siphon - that would be bad! The other option would be to plum the suction side of the CL through the bottom of the tank. Check out 'Mike's 300DD' thread in the large tank section as that is what he did.

 

[jdarr]

I'd have to think about the siphon break. I think as long as any standpipe that shares the overflow with the CL suction side is near the top of the tank you will be OK. Under no circumstances should you have the herbie siphon in the same overflow, otherwise in the event of a power loss your tank would drain down to the top of the herbie siphon - that would be bad! The other option would be to plum the suction side of the CL through the bottom of the tank. Check out 'Mike's 300DD' thread in the large tank section as that is what he did.

Yeah, I was thinking of removing the CL intakes altogether, and just having the weir taking all the return pump water, with the return pump being ran back into the tank and plumbed to the bottom near the rocks etc (with a syphon break drilled in that line near the top of the waterline on the tank side of the plumbing).

I've looked at his thread many times lol, I'll have another look!

 

[Aquatron]

The flows given off by MPs/powerhead/wave boxs are different than by a close loop system. Learning the different ocean flows where corals live will help a hobbiest decide which they wish to use or leave off their build. Cost is not really a factor for those who have installed and used a well designed close loop system. Try creating a vortex flow or turbulance's at more than one spot with MPs but then a close loop set up doesn't make a 2" wave either. The more you know the better you flow....lol but true

 

[NeilFox]

I like closed loops. I don't think you even need an overflow for it. I really like David Saxby's design it does more than any mp40 could. Sea swirls are pretty awesome too. Even though it's 2013?

 

[rlpardue]

A closed loop is good for hitting dead zones behind rockwork that Vortechs don't touch. I have my C/L outputs directed to the corners of the tank and behind rocks. My MP40 gets the main mass of water moving though and I wouldn't want to live life without it.

One thing you should google is "NPSH" (net positive suction head). It's a principle that applies to closed loop intakes. To summarize, you need to have water "pushing down" the intake of the CL pump; this is done by having the intake positioned with a minimum depth of water above it. I don't think an overflow box would allow you to get the NPSH you need to keep the pump performing optimally. Just put a couple of discreet intake strainers behind a couple of rocks, midway down the back wall.

Also, an overflow box will probably generate air bubbles that will go through the pump and on through the outputs.

 

[ReefKeeper64]

I run a closed loop in a 109g rimless and may be able to give some experienced advice since you are asking. You have the right idea as you can a have a tremendous amount of ultra quiet flow without seeing pumpheads. Your drawing shows a fake back panel design.

1 - Cut back on the number of holes in your tank. Consider a 4 way instead as fewer parts mean less work and less cash. Invest in sch80 bulkheads for the ones you do drill. The seals and materials will last much longer than sch40.
2 - You don't want surface water returning to your CL. That water is the dirtiest in your tank and any layer of oil on the surface would be recycling in your display tank. You don't want that. You want all the surface water to drain into your sump where your filter sock and skimmer are. Instead, just divide your fake back into two sections (a left half and right half). It kinda looks like you are trying to do that alrady. On one half, you have a traditional overflow over the top and all surface water returns to your sump area.

3 - On the other half, you have your thin vertical slots cut into your fake back about 5-8 inches from the water surface level. Don't have any overflow slot on the top with this half. This is for the closed loop water flow which will be all submersed water. You can loose a good portion of the water in your tank without ever having the risk of running your pump for the CL dry and yet you can still make your overflow area dry if you ever need to for a repair issue.

4 - instead of having those pipes going up and over the fake back, just get that fake back drilled for those pipes a few inches under the water level and run the plumbing through those holes using bulkheads. This will give you a much more finished look as you won't see a bunch of pipes skicking out of the water and over that fake back. Instead, you will have pipes that are fully submersed and you can hide them better. If you ever need to do maintenance, you can just lower your water level below where those holes are and then no water can make its way into your overflow area on the left side with the traditional overflow.

5- Not sure I would bother with an 8-way. Putting my system together was alot of work. I use an OM-4 way and it creates a ton of mixed flow without as much plumbing to deal with. Just request their 1/5" diameter OM unit to get max flow.

6-Your drawing doesn't show union valves and you are probably already planning to use those but be sure to include them. You will want to be able to dial back the flow a bit on certain outlets to tune it once it is up and running.

Chris

 

[jdarr]

The flows given off by MPs/powerhead/wave boxs are different than by a close loop system. Learning the different ocean flows where corals live will help a hobbiest decide which they wish to use or leave off their build. Cost is not really a factor for those who have installed and used a well designed close loop system. Try creating a vortex flow or turbulance's at more than one spot with MPs but then a close loop set up doesn't make a 2" wave either. The more you know the better you flow....lol but true

Thanks Aquatron!. In my previous system, I used 4 x tunze 6105 set up with a wave pulse, and prior to that I had to return pumps that moved the water around. I really came to enjoy the pulsing, the livestock seem to really like a lot as well. I am kind of leaning toward that again, yet, every time I look at Stuart Bertram's tank I drool (lol) and he is using strictly closed loop and his tank dimensions are very similar.

I guess I am looking for the best of both worlds while also limiting how much equipment I put in the system... Pondering :rollface:

 

[jdarr]

I like closed loops. I don't think you even need an overflow for it. I really like David Saxby's design it does more than any mp40 could. Sea swirls are pretty awesome too. Even though it's 2013?

Yeah, the concept of putting the CL's in the overflow was just to hide everything... I want to access the suction lines in case of emergencies etc and I hate the look of strainers, so I was curious to see if anyone knew of pitfalls with this concept (and some have certainly been pointed out! Thank you everyone)

 

[jdarr]

Also, an overflow box will probably generate air bubbles that will go through the pump and on through the outputs.

WOW great point... never considered this...

 

[jdarr]

I run a closed loop in a 109g rimless and may be able to give some experienced advice since you are asking. You have the right idea as you can a have a tremendous amount of ultra quiet flow without seeing pumpheads. Your drawing shows a fake back panel design.

1 - Cut back on the number of holes in your tank. Consider a 4 way instead as fewer parts mean less work and less cash. Invest in sch80 bulkheads for the ones you do drill. The seals and materials will last much longer than sch40.
2 - You don't want surface water returning to your CL. That water is the dirtiest in your tank and any layer of oil on the surface would be recycling in your display tank. You don't want that. You want all the surface water to drain into your sump where your filter sock and skimmer are. Instead, just divide your fake back into two sections (a left half and right half). It kinda looks like you are trying to do that alrady. On one half, you have a traditional overflow over the top and all surface water returns to your sump area.

3 - On the other half, you have your thin vertical slots cut into your fake back about 5-8 inches from the water surface level. Don't have any overflow slot on the top with this half. This is for the closed loop water flow which will be all submersed water. You can loose a good portion of the water in your tank without ever having the risk of running your pump for the CL dry and yet you can still make your overflow area dry if you ever need to for a repair issue.

4 - instead of having those pipes going up and over the fake back, just get that fake back drilled for those pipes a few inches under the water level and run the plumbing through those holes using bulkheads. This will give you a much more finished look as you won't see a bunch of pipes skicking out of the water and over that fake back. Instead, you will have pipes that are fully submersed and you can hide them better. If you ever need to do maintenance, you can just lower your water level below where those holes are and then no water can make its way into your overflow area on the left side with the traditional overflow.

5- Not sure I would bother with an 8-way. Putting my system together was alot of work. I use an OM-4 way and it creates a ton of mixed flow without as much plumbing to deal with. Just request their 1/5" diameter OM unit to get max flow.

6-Your drawing doesn't show union valves and you are probably already planning to use those but be sure to include them. You will want to be able to dial back the flow a bit on certain outlets to tune it once it is up and running.

Chris

Thanks for all the info Chris!

Point 1***
I was actually considering 2 closed loop systems (2 x 4-ways) this way I had redundancy with the pumps etc etc. But your comments affirm another concept that I have been considering - going over the top if the tank. (aquascape concept to hide the pipes and it's in wall so no one will see above the water)
For an example please see this link:
http://www.youtube.com/watch?v=C30zRuTfcjk&list=PL58D40CE192F0FB0D

Point 2&3***
GREAT info. Thanks I had not considered the surface skimming at all...

Point 4***
See point 1

Point 5***
See point 1

Point 6***
Yes, I was planning on true union valves.

Do you think one 4 way would be enough for a tank this size? Maybe instead of 2 x 4-ways, i could do 1 x 4 way and a couple MP60?... pondering out loud lol

Thanks for the thorough input I really appreciate it.

 

[ReefKeeper64]

Thanks for all the info Chris!

Do you think one 4 way would be enough for a tank this size? Maybe instead of 2 x 4-ways, i could do 1 x 4 way and a couple MP60?... pondering out loud lol

A single OM 4 way should be fine. Use a big pump and Y splitters to channel back out to 8 returns if you like but again probably not necessary. I have to dial mine back to avoid water splashing out of the tank and to keep sand covering the entire bottom of my tank. A word of warning about the OMs, they may make a knocking noise, mine do/did. It comes from different final pressures in the plumbing and the fix is to dial back one or two of the returns until the pressure is equalized. Not a big deal if you have the valves but some folks who didn't install those have been disappointed because the moving barrel inside the unit will thump around in the chamber if not balanced.

Another option to consider is copying David Saxby's closed loop. This is what I would do if I was doing this over and especially with a larger tank. He uses dedicated pumps that turn on and off with a timer. The new DC pumps would work great for this purpose with their slow ramp up even through his are AC pumps and seem to work flawlessly.

http://www.theaquariumsolution.com/files/Technical review of David Saxbys system2.pdf