Sump flow rate

[dlsrks]

I have a Fluval FX5 on my 140 tank. I am going to set up a sump. The tank already has one predrilled overflow on each end of the tank. I'm going to open those and use them to flow water to the sump. I have some questions though. I plan to DIY. I understand from the Internet that 1" overflow is roughly 950 gph. So for both flows if I keep the water high enough, it would be 1900 gph. When I put on the slip bulkhead strainers, would be the flow rate? Too sure how to calculate the reduced flow rate. I want to be able get the right size return pump. Also what size sump do I need? Hopefully i can get by with just one but i have two extra 20 gallon tanks. But only one will fit under the cabinet. If I use both of them, how would I connect them and which one should I put the fuge in? Sorry so many questions but I only want to do this once since I have two other tanks.

 

[jeffaquarius]

With 1" overflow at both ends and strainer you can have 1900 gph return pump. You can always reduce the rate of flow by installing a ball valve on the return pipe. A 20 gal sump may be a little bit small but with the ball valve you can upgrade any time. I have a 10 gal sump on my 60 gal DT and so far so good. If you can elevate the other 20 gal for refugium higher than the sump, use the same set up as DT for overflow and install a Y on one overflow from DT as a splitter then provide a 2nd ball valve to provide a low flow for refugium.

 

[Gti_Leo]

you shouldn't need mroe the 1000GPH flow rath through your sump that would be the most i'd go for i'd prob go with a 750, you don't need a fast rate through your fuge and you want your skimmer to get as much nutrients out as possible, you won't with a high flow rate

 

[jeffaquarius]

The ball valve will adjust the flow rate of return pump to as much as 50% that will suit the 20 gal sump. It's better to have a bigger pump for future upgrade. Having a valve at the fuge, the flow rate can be adjusted up to 0 flow if you want while the rests go to your sump. The skimmer can be installed with its outlet back to the reservoir of your return pump while the inlet is separated or isolated from outlet. You can then split the return pump output to your DT.