One Return Line instead of Two?

[Patrick Cox]

I am planning a new build and I am thinking I would prefer one return line to the display instead of two, which I have on my current tank. The tank will be 48or 54x24x20. My reasoning is that with one return line, I can greatly simplify my plumbing. Also, even though I have two return lines currently, I still just have one return pump so aren't I just running less water through those two lines? Also, I have my variable return pump dialed back and my drain gate valves are fairly closed so I am not pushing a ton of water through the tank anyway. The only benefit I can see of two return lines is you are pushing water from the sump to two spots in the display instead of just one. And I am not sure there is much benefit to that but I could be wrong.

My drain will be an external overflow box with Bean Animal (3 lines.)

So thanks for your comments on this.

Pat

 

[mfinn]

No reason why you can't use 1 return line.
Many do it, including myself.

 

[Patrick Cox]

No reason why you can't use 1 return line.
Many do it, including myself.

Would you keep the overflow in the center with one return? Or off to the other side? Thanks.

 

[Dmorty217]

I would put them at opposite sides from one another to maximize the skimming potential of the overflow box

 

[Patrick Cox]

I would put them at opposite sides from one another to maximize the skimming potential of the overflow box

When you say opposite sides, do you mean something like this?...

Thanks!

 

[Dmorty217]

When you say opposite sides, do you mean something like this?...

Thanks!

Yes. Just so the water that's being pumped in the tank from the return pump isn't immediately then taken in by the overflow

 

[Ron Reefman]

I have 3 return lines. Two run full time and one is just an emergency return. Think about what happens if you have one return and it gets plugged up by a snail that gets into the pipe (it happens)?

Deal with the extra plumbing now and avoid the flooded floor later!

 

[kmbyrnes]

Since the return is not doing much anything other than delivering the dirty water to your skimmer and sump, one line will be fine. Your Power heads should be what provides the flow in your tank.

 

[Patrick Cox]

I have 3 return lines. Two run full time and one is just an emergency return. Think about what happens if you have one return and it gets plugged up by a snail that gets into the pipe (it happens)?

Deal with the extra plumbing now and avoid the flooded floor later!

Are you referring to the returns (return to Display Tank) or the Drains? I will have 3 drain lines (Herbie system.) I am not sure how an emergency return line would work.

Thanks.

 

[mfinn]

I have 3 return lines. Two run full time and one is just an emergency return. Think about what happens if you have one return and it gets plugged up by a snail that gets into the pipe (it happens)?

Deal with the extra plumbing now and avoid the flooded floor later!

I believe the op is talking about the RETURN lines, not drain lines.
A snail would find it difficult to crawl into a return line with the pressure of the return pump pushing water out of it.

I have 3 drain lines ( bean animal style) that has the emergency drain option too.

 

[mfinn]

Would you keep the overflow in the center with one return? Or off to the other side? Thanks.

This is a drawing the tank manufacture sent me for final approval.
The single return line is up in the upper left corner.

 

[Patrick Cox]

This is a drawing the tank manufacture sent me for final approval.
The single return line is up in the upper left corner.

Thanks, this is interesting. Who is building your tank?

 

[ca1ore]

In a modern reef tank (where in-tank circulation is achieved with powerheads and wavemakers) splitting returns is unnecessary, and simply serves to put greater back pressure on the pump. 20 years ago, when the available in-tank flow options were limited, using the main pump to aid circulation was necessary, and splitting the returns useful. Today it's an anachronism and not useful.

On my tank, in a effort to reduce power use as much as possible, my main return runs up a single pipe, with as few turns as possible and absolutely no loc line.

I also don't think it makes much difference where the return outlet is located (as long as it's at the surface), just don't direct the jet of water right at the overflow, obviously. I shoot mine straight down behind the rockwork.

 

[mfinn]

Thanks, this is interesting. Who is building your tank?

Oceans By Design in Tukwilla Washington, built it about a year and a half ago.

 

[Ron Reefman]

I believe the op is talking about the RETURN lines, not drain lines.
A snail would find it difficult to crawl into a return line with the pressure of the return pump pushing water out of it.

I have 3 drain lines ( bean animal style) that has the emergency drain option too.

My bad, I misunderstood the issue. :uhoh3:

 

[Xxero]

It's funny because I spent all weekend doing this. :lmao:

I've had 2 return lines since the birth of this tank, and I made the same observation as you.....It was a waste. I re-plumbed my sump to just 1 return line, and I like it so much better. By simplifying the plumbing, it increased the output flow tremendously. It also removed one more unsightly pipe running up and over the back of my DT.

I'm glad that I did it. :bigeyes:

 

[Patrick Cox]

I have been getting quotes on a new build and one builder told he he likes two returns because it creates more surface movement. That makes sense but I am not sure if it really creates a healthier environment for fish and corals.

 

[mfinn]

My bad, I misunderstood the issue. :uhoh3:

I do it on a pretty regular basis.