My pump is too strong for my overflow.

[Anonymous]

It seems I got a stronger pump than I needed. Can I put a valve on this or will that harm the pump. The overflow can't keep up with the return.

The pump is rated 900 gph, pumps water up 4.5 feet and around three 90 degree bends, which I understood should make it the equivalent of about 7 ft. Apparently that calculation is a bit conservative. My return is 1.25".

Help.

 

[RobertoVespucci]

I think it depends on how the pump is constructed. The impeller type do well with a little backpressure since they can slip.

 

[Anonymous]

I would think that 1.25" drains could handle that flow.

Are there any bends in the drain lines?

If you do put a ball valve in line with it, do it on the output side of the pump. Restricting the flow on the input side can damage the pump.

Louey

 

[Anonymous]

Is there any kind of restriction in the drain?

 

[Anonymous]

None that I am aware of. I am not 100% certain it can't handle it yet. I sort of lost my nerve. The water level goes up above the street L, which I assume is bad, right? At that point I turned off the pump.

 

[Len]

You can put a valve to choke back the pump's output. But 1.25" drain should handle 900gph without problems.

 

[Anonymous]

Ok, maybe I am just being a wuss.

 

[Anonymous]

Sorry, it is a 1" bulkhead. 1.25" standpipe. Guess I shoulda got two overflows.

 

[Anonymous]

Maybe I should T it off to my skimmer or something?

 

[Anonymous]

Even a 1" should be able to handle 900 gph. Sometimes it goes a bit above the elbow.

 

[Anonymous]

I have a 1200gph pump and my head is about 7 ft-ish. I have a 1 inch drain with no problems. Are you certain your drain isn't clogged or something else in the line from tank to sump that is causing backage or stoppage?

 

[Anonymous]

Well assuming the world of hydrodynamics works differently on your plumbing system I would NOT put a valve to restrict the flow, on the other hand I would put tee off the pump and put a valve on that that goes back into the sump (or a refugium or something that could use a little flow)

 

[Anonymous]

The toilets flush clockwise here I think...lol

 

[Anonymous]

Well, even with the valve fully open, it is fine, leading me to believe I don't really need the valve. Or else the connection is leaking under water. There is no blockage. I am probably being a wuss.

 

[Anonymous]

I looked it up in Delbeek and Sprung, The Reef Aquarium, Volume 3.

At 12" water height, a 1" ID bulkhead can keep up with 900 gal/hr. Mine is somewhere around 16", so the flow rate will be faster.

The 1" bulkhead should not therefore be rate-limiting. Now do I have the courage of this conclusion?

 

[Anonymous]

Don't watch the water in your overflow while you are testing this, watch the level in the main tank. If it goes up over the top of the overflow teeth then you have a problem, it doesn't really matter about the water level in the actual overflow. Plus the more water on top of that elbow the more force there is shoving the water down the pipe...

So, grow some cojones and crank that puppy up!

 

[Anonymous]

Turn the damn thing on and let it run, man.

 

[Anonymous]

If you are having problem you can put a valve on the output side of a pump with no problels unless you shut it all the way. Never throttle a pump on the suction side.

 

[Anonymous]

Did you adjust the air nozzle/hole on the Durso? By adjusting how much air the Durso can take in, you can change the level of water in the overflow.

 

[Anonymous]

Yeah, it goes quite high when the cap is off, and if you plug the hole it drops and slurps siphon-style. So I am still working on getting the right diameter hole. I think I freaked myself out a bit too much by watching what was going on in the overflow.

I tend to be paranoid about these things.