# how many GPH for 125 gallon on tank



## t0rns0ul (Dec 27, 2008)

Tank setup will be similar to fmueller 240G (which by the way is one of the nicest Frontosa setups Iâ€™ve seen) but on a smaller scale, so maybe he can shine a guiding light onto this question??

My setup needs to support Tanganyika fish community, approx 50-60 juvenile fish and runts to be sold off as fish mature...

--125 gallon show tank (18"D x 24"H x 72"L)

--Two corner box overflows (4"d x 8"L x 7"H) each containing one 2" bulkhead that drains to its own sump

--Two sumps holding 12 gallons each for a total of 24 gallons (sumps connected to each other to keep water flow, level)

--5' tank head height

--Returns will end at UGJ system to keep water column moving upwards to overflows

I want to run two pumps, one in each sump for redundancy. What would be the most efficient GPH for this tank setup?

I was looking at the following

Two ViaAqua VA4900, 1321GPH 0', each
With 5â€™ head height about 800PGH each, for a total of 1600GPH. 
Factor in another 100-200GPH loss on the UGJ system, 
So Iâ€™m guessing I would end up with about 650GPH per pump 
An approximate total of 1300GPH

Would that be too much?


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## Morpheus (Nov 12, 2008)

I _think_ the rule of thumb is 4 to 5 turnover for a cannister and 8-10 times for a sump, so I believe you are right in the ballpark. By the way, I have a Via Aqua and I absolutely love it.


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## t0rns0ul (Dec 27, 2008)

I've researcehd that 10 time turnover is good for sump filteration which is what fmueller hit on his 240 and what im aiming for. I just dont want the curent to be to strong and blow the fish all around.

Thanks for the feedback, anyone else want to share their thoughts?


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## Hoosier Tank (May 8, 2007)

Sounds like you have a good grasp on things. You already understand head loss and restrictions in the UGF piping causeing a reduction in flow. Probably don't want to get into the brand name discussion as you will be forwarded to the "Reviews" section. Good job on researching the numbers though.... I think you're on top of it.


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## Rockydog (Oct 21, 2007)

> --Returns will end at UGJ system to keep water column moving upwards to overflows


This is not a good idea because in a power outage your tank will siphon to the level of the jets and cause a disaster. Check valves would work but are not reliable. I would forget the UGJ and just use a couple of powerheads to keep the detritus suspended until it is filtered out.


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## Hoosier Tank (May 8, 2007)

Rockydog said:


> > --Returns will end at UGJ system to keep water column moving upwards to overflows
> 
> 
> This is not a good idea because in a power outage your tank will siphon to the level of the jets and cause a disaster. Check valves would work but are not reliable. I would forget the UGJ and just use a couple of powerheads to keep the detritus suspended until it is filtered out.


I did it... All you need to do is drill a hole just above the water level in the tank on your return line to the UGJ. I actually went so far as to add a nozzel right at splitting the surface and another 1/2 way down. This not only provides surface aggitation but acts as a siphone break in a power outage. I turn off the pump every week to perform my water change and it doesn't back-siphone. You can almost see it in the top right of each picture


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## t0rns0ul (Dec 27, 2008)

Rockydog said:


> > --Returns will end at UGJ system to keep water column moving upwards to overflows
> 
> 
> This is not a good idea because in a power outage your tank will siphon to the level of the jets and cause a disaster. Check valves would work but are not reliable. I would forget the UGJ and just use a couple of powerheads to keep the detritus suspended until it is filtered out.


Good point and I should've pointed this out in my thread start.

The setup I just broke down to start this new project already had a sump with return pipes ending underwater. I tried the check vavles, but to get the valves to push open you lose more GPH, plus sand caught in valve can cause failure. So, I switched up to a small pinhole drilled in just under the water surface to break syphon in the event of pump loss.


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