One return line or two? How many holes to drill

[RobertK]

Hey all,

I'm getting ready to order a new custom tank. It will be ~110 gallons, 60x21x21" with an internal overflow box in the center of the back wall. External overflow is not an option. Sump will be in the stand below. The tank will be up against a wall, so the overflow box will be difficult to access. I want to set it up in the most foolproof and cleanest looking way possible.

I will have 3 holes drilled in the bottom of the overflow box for 1" BeanAnimal drain pipes. I'm undecided on the return lines but they will require additional holes drilled.

I think I'd rather have the return lines come up through the overflow box rather than through the back wall or over the top. But should I have one 1" return line entering the overflow box that tees into two 3/4" lines inside the overflow, or two separate 3/4" return lines in the overflow box? And should I run the return lines over the top of the overflow box or have the sides of the box drilled for outlets?

I'm open to any and all suggestions. Thanks!

 

[JumboShrimp]

Two. Even with a small Innovative Marine 20 gallon, I appreciate the ability I have to point two flaired return nozzles in two different directions near the surface of the water. (Then a wavemaker for deeper flow.) Best wishes!

 

[X-37B]

I prefer no returns in the overflow.
I have 2 systems with returns in the back wall and 1 with a return in the Center overflow. The center return works well and is never an issue as tanks 20" front to back.

 

[RobertK]

Thanks for the replies.

Two. Even with a small Innovative Marine 20 gallon, I appreciate the ability I have to point two flaired return nozzles in two different directions near the surface of the water. (Then a wavemaker for deeper flow.) Best wishes!

I might not have made myself clear but I will have two return nozzles either way. The question was whether to drill two holes for two 3/4" bulkheads and two separate return lines, or one 1" bulkhead that tees to two lines inside the overflow box. The former option would allow me to run two return pumps for redundancy (and without check valves) or I could tee off a single return pump before the return line hits the overflow box. The latter option would allow for a smaller overflow box but I wonder if thats too much stuff going on inside the box.

I prefer no returns in the overflow.
I have 2 systems with returns in the back wall and 1 with a return in the Center overflow. The center return works well and is never an issue as tanks 20" front to back.

Can you elaborate a bit on why you prefer no returns in the overflow? I'm open to not doing that but I don't really like the look of pipes or locline entering the tank, and am trying to minimize their visibility.

 

[Tripod1404]

I also dont like returns on overflow box. Not that anything is wrong with that, but in my opinion, it makes plumbing complicated since a lot of piping is cramped together.

 

[X-37B]

Thanks for the replies.



I might not have made myself clear but I will have two return nozzles either way. The question was whether to drill two holes for two 3/4" bulkheads and two separate return lines, or one 1" bulkhead that tees to two lines inside the overflow box. The former option would allow me to run two return pumps for redundancy (and without check valves) or I could tee off a single return pump before the return line hits the overflow box. The latter option would allow for a smaller overflow box but I wonder if thats too much stuff going on inside the box.



Can you elaborate a bit on why you prefer no returns in the overflow? I'm open to not doing that but I don't really like the look of pipes or locline entering the tank, and am trying to minimize their visibility.

You said it above. Too much stuff in the box.
Your returns don't need to protrude into the tank. Just don't use them. It can be flush with the back wall.
If you drop something into the overflow box the return makes it harder to get. With just drains you can pull them out and flush the box if needed.
It's really just what you like best as I prefer the back wall option.

 

[RobertK]

I also dont like returns on overflow box. Not that anything is wrong with that, but in my opinion, it makes plumbing complicated since a lot of piping is cramped together.

You said it above. Too much stuff in the box.

Great point, glad I asked! I'm already nervous about access to the overflow box on the center of the back wall. One time a fish got into my corner overflow and it was hard to get him out even though I could see him through the side glass!

Your returns don't need to protrude into the tank. Just don't use them. It can be flush with the back wall.

So I can just have a couple of bulkheads on the back wall of the tank with no pipes entering the tank? Would black ABS bulkheads be OK to match the black vinyl on the back wall of the tank? Would that be quiet or would it gurgle?

If you drop something into the overflow box the return makes it harder to get. With just drains you can pull them out and flush the box if needed.

So with a BeanAnimal drain in an internal overflow box, would all 3 pipes just be press fitted into a slip bulkhead opening, so that all 3 pipes could be pulled out if necessary?

 

[X-37B]

Great point, glad I asked! I'm already nervous about access to the overflow box on the center of the back wall. One time a fish got into my corner overflow and it was hard to get him out even though I could see him through the side glass!


So I can just have a couple of bulkheads on the back wall of the tank with no pipes entering the tank? Would black ABS bulkheads be OK to match the black vinyl on the back wall of the tank? Would that be quiet or would it gurgle?



So with a BeanAnimal drain in an internal overflow box, would all 3 pipes just be press fitted into a slip bulkhead opening, so that all 3 pipes could be pulled out if necessary?

Yes press fit only.

These are the 3/4" returns used on my ext systems.
You can buy them from IM.
Small hole small nut in tank.

 

[X-37B]

Here it is in my system with locline for reference.

 

[UncommonSense]

Would black ABS bulkheads be OK to match the black vinyl on the back wall of the tank?

These will work, but are the most brittle (and often cheaply made) variety, typically!

Polypropylene bulkheads often come in black, and some PVC bulkheads can be optioned in black! — “thru-hull fittings” could also work here!

Would that be quiet or would it gurgle?

It wouldn’t gurgle at all, especially if return nozzles are fully submerged, such as when employing the likes of RFGs!

— the only challenge is an anti siphon device for power outages/pump shutdowns, given that the bulkheads are likely to be mostly to completely submerged… a hole drilled in the in-tank plumbing stub prior to any return nozzle would likely still work, or other methods can be used!

 

[RobertK]

These will work, but are the most brittle (and often cheaply made) variety, typically!

Polypropylene bulkheads often come in black, and some PVC bulkheads can be optioned in black!

Great, thanks for that info. I thought you had to go with ABS if you wanted black.

the only challenge is an anti siphon device for power outages/pump shutdowns, given that the bulkheads are likely to be mostly to completely submerged…

Would it be safer to drill holes in the euro brace and bring the return lines over the top?

 

[UncommonSense]

Would it be safer to drill holes in the euro brace and bring the return lines over the top?

You could, but it does weaken the eurobrace to drill it!

I think something like a locline wye (or other form of compact plumbing tee/wye), possibly a reducing wye; 3/4” in, dual 1/2” out…

This lets you submerge one nozzle per-return, and leave the second nozzle emerged, or near the water’s surface when in operation!

This hasty sketch should help to explain what I’m imagining… note: it can be made much more compact, I drew it too small and thus expanded parts for visibility!