Overflow combiner

[karimwassef]

I have three 2" overflow pipes in my DIY garden reef pond, but I only want one 2" pipe to go to the back sump...

If I combine the three pipes and add a riser that's higher than the tank, would that work? What if the riser pipe is 6" reduced to the 2" of the overflow pipes.

I don't think so personally.

I would expect that each pipe needs to have it's own 2" riser before they're combined.

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[karimwassef]

like this

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[Gorgok]

Why have three pipes if they are all going to be open to air and tied together (so all wet all the time).

By the look of it you will have maybe a foot? of head in the system... How much are you trying to flow?

[karimwassef]

The three pipes are the standard that I use to tune all my tanks.

One is full bore siphon. One is throttled/tuned. One is emergency open.

I'm hoping the risers emulate an open sump... then I combine to go into the real sump.

In this design, both DT and sump are technically sump with flow between them. The overflow is to create surface skimming in the "DT sump" without noise.

The ATS is actually the "tank" in conventional systems

[Zephrant]

Not going to work- You can't combine a full-bore 2" siphon with a throttled 2" pipe, both in to a 2" pipe. And there is no reserve capacity left for your emergency pipe.

Might get it to work if you went to a 4" or 6" pipe to the sump, but even then it might end up being pretty touchy.

Pipe your emergency pipe in to a new bulkhead, just above the water line of the sump, at least.

[karimwassef]

ok.. so emergency goes direct.

Can the other two merge with pre-combiner risers into a 4" pipe?

[mcgyvr]

I'm with Gorgok..
Why even run an overflow setup?
Just adding complexity that doesn't need to be there..

[karimwassef]

The flow rate is about 5000gph

Well... an open top can get very very loud....

While this is all outside, I really don't need neighbors complaining :)

The two pipes allow me to tune them to run in siphon mode

[karimwassef]

also- I can't afford the larger pvc valves in case I go bigger... I could go for a single 6" for example, but I would not be able to separate the two loops.

[mcgyvr]

just have the pipes underwater (3 bulkheads just like you have now) the tanks will (should) stay consistent even pumping water between them..
You don't have the same concerns as a normal tank setup so you don't need an overflow..

[karimwassef]

I still need to surface skim without noise.

The incoming water is at 5000 gph... that will create ~ 1" of head over the pipes. The slurping will be silly.