How to deal with to much return flow

riche · Apr 22, 2016

I picked up a reeflo dart/snapper hybrid and it only has the the bigger impeller.

So Its pushing around 3600 gph which is going to be to much since Im using it on a 180 and only have about 6-7ft total head going thru dual 1" returns.

I am going to make a manifold for my reactors and uv, but I'm thinking iI'm still going to have a little to much.

Could I use a ball valve to turn it down or will that hurt the bump over time?

or could I run a "pipe for blowoff" like you do a air pump and and have it dump into the return area?

thrasher1472 · Apr 22, 2016

Ball valve should be fine, I would assume it's kind of like adding head pressure. If you need more flow in your refugium you could run a pipe over but I think a ball valve would be helpful.

NeptuneGarden · Apr 22, 2016

back pressure on a pump does not hurt it. Only thing you want to avoid is ever having enough back pressure that flow stops to zero.
only thing that will happen is you will use less power. Dumping it back into the sump is fine, but of no benefit.

Always restrict the outlet, never the inlet

the only thing you never want to do is to recirculate the output directly back into the input, or the pump can runaway and "over amp"

JimDog2015 · Apr 22, 2016

IMO I would not restrict the flow from your pump. That can cause your return pump motor undue stress. I would cut in a tee into the tank return and that branch would returned water to the sump, and then put a valve on that additional return to regulate that return as needed.

Browner20 · Apr 22, 2016

Yes, you can use a ball valve to dial down pressure. I had a large external pump on a 20 gal long once and used a runoff pipe back in to the sump. I purchased a bunch of live rock for the tank and just put all of the rubble in an old overflow box and had the runoff pipe running the extra water back through the rubble for some extra biological filtration. Pods were growing in there like crazy so it also acted like a pod breeding ground.

Browner20 · Apr 22, 2016

FWIW - I have a Dolphin Amp Master 3500 on a 60 gal tank with 4 1" returns and can run it full without issue. It has about 3ft of 1.5"PVC before it Ys into 2 1" runs of about 1ft and then each of them split into 2 1" returns right at the tank so I have some additional head pressure from additional plumbing, unions, and elbows.

Basically - if I had 180 gal tank the dart/snapper would be a good pump to use especially to run a manifold to a reactor, refugium, etc. You may use a ball valve to dial back a little but probably not if you can split the 2 returns into 4?

I dial mine back just a hair to avoid having to change the filter socks as frequently. I kind of like the high flow through the sump area because it keeps and detritus from building up.

HOWEVER - you need to make sure your drains can handle the flow!