Return pump to strong?

[baldbean]

Hi all.

 

I am testing my new system out and noticed that return pump may be too strong. I am running a Glass-holes overflow (nano con dientes -- 300 gph) and an Ehiem 1250 (317 gph).There is lots of air in the drain line entering the sump and I can hear gurgling coming from the little tubing coming out the top of the elbow attached to the overflow box. Its pretty loud. However I noticed that when I restrict the return line via the ball valve the gurgling and air stop, making it much more quiet. The ball valve is more than half closed.

 

Here are my questions:

1. Is restricting the flow this much bad for the pump and/or return plumbing.

2. What should the flow be through the sump? 3 to 5 times the DT? I think I aimed too high...

3. Would a smaller pump be better? (Eheim 1048, 158 gph)

 

Thanks!

 

EDIT: There is about 3ft of head from the sump to the DT.

[seabass]

1. Is restricting the flow this much bad for the pump and/or return plumbing.

No, the pump will actually use less electricity when restricted. The recommended flow for that overflow is between 1 and 200gph.

 

2. What should the flow be through the sump? 3 to 5 times the DT? I think I aimed too high.

The DT flow is provided by powerheads, and is determined by your livestock needs (generally 20 to 50 times turnover). The return pump provides flow through the sump (which could vary based on overflow, drainpipe, sump equipment and/or refugium).

 

3. Would a smaller pump be better? (Eheim 1048, 158 gph)

You could just use the valve to provide the flow that you want. Or you could get a cheap pump like a Cobalt MJ1200.