Single or dual returns

[raultsu]

I’m thinking about getting a custom tank but I don’t know if I should get it drilled for 1 or 2 returns. I’m thinking about a 48” 120 gallon tank. What do you suggest?

 

[JumboShrimp]

“Custom” is a great feeling, because it means you’re in charge of everything. I’d suggest to go with two (2). Best wishes!

 

[ca1ore]

Depends. Do you need return flow to supplement powerheads? Do you have bandwidth to spare on the return pump? If yes, then 2; if no then 1.

 

[fermentedhiker]

I like to use two return pumps for redundancy so if one fails while I'm away at least everything will still be fine until I can fix it. So I would go for two returns(one for each pump). If you're only using one return pump I don't suppose it makes much difference since most of your in tank flow will come from your powerheads.

 

[Tastee]

I run a RSR250 so are limited to 1 return but if I was building a custom tank I would definitely have 2 so I could have redundancy on the return pumps.

 

[mfinn]

All you are doing with a return pump is returning water from the sump to the display tank.
Use this as a single purpose and go with one return. Buy a good dependable pump and you will be fine.
With a custom tank build, get fancy with the drains and go with either a herbie ( 2 drains) or bean animal ( 3 drains) design.
Alot of headaches people encounter are with noisy drains.

 

[Blue Spot Octopus]

A Fluval SP 4 will be more than enough pump and should be bullet proof for the next 10 plus years. The pump is very large but it can be ran external. This pump can be too much for a slow type return flow, but perfect for a ghost type overflow.

 

[davocean]

I think you mean dual return lines and not dual return pumps.
I would only use one return pump, and dual lines would depend on tank size, overflow, but for example my 120g is center overflow w/ 2 lines coming from that.
Flow from sump is very low, I don't rely on that for display flow really, but my 2 lines do help hit behind rock work for me resolving some dead spots.

 

[WVNed]

I use 2 because a single return becomes a fire hose like stream you have to point at something.

 

[tb582]

Curious - does anyone spit their one main return to end up with 2 at the tank? I too assume most aren’t using 2 return pumps, and I have 4 hard plumbed lines and would rather use 3 as drains and 1 as the return but split it at the tank J-tubes

 

[Eggs]

I’ve done that with 150g and 180g tanks. Used a y-shaped pvc fitting. You may have to order it online, don’t recall if the big box stores carry it, don’t think they do.

 

[mfinn]

Curious - does anyone spit their one main return to end up with 2 at the tank? I too assume most aren’t using 2 return pumps, and I have 4 hard plumbed lines and would rather use 3 as drains and 1 as the return but split it at the tank J-tubes

There are so many different ways to plumb the drains and return lines.
Many use 2 pumps ( I don't )
There is nothing wrong with going with 2 returns. There is nothing wrong going with a single.
Plumb the tank the way you want and don't worry about what others may say you need to do it their way.

I've split the return before the tank and run 2 returns, and it worked fine.
I currently have a single return line and return bulkhead. On the inside of the tank I used a loc-line Y and 2 fan nozzles.

 

[exnisstech]

I currently have a single return line and return bulkhead. On the inside of the tank I used a loc-line Y and 2 fan nozzles.

This is exactly how my 180g was set up except I went over the top because it wasn't drilled. Rather than running two pumps I just kept spare on hand but I don't travel. I also use my returns for filtration not flow. I depend on in tank powers heads for that.