Flow restriction - hard on the pump?

[jgreen1025]

My old return pump burned out and I finally replaced it with a QuietOne 3000, but I'm afraid it's TOO powerful. I've added a second U tube to the overflow and widened the slot on the pipe holding the screen, but the water level in the tank still seems to keep rising to the point where I fear it'll overflow. My last option is to install a valve in the return plumbing to control the flow back up to the main tank, but I'm worried that this will put undue strain on the pump. Is this a legitimate worry? Or is this standard practice?

John

[SantaMonica]

Is more a question for a regular reef forum, in their plumbing or filtration forums.

I'll move this to the general section

[kcress]

jgreen; That is one of the most pernicious fables in aquarium land.

You may restrict the output of your centrifugal pumps all you want with NO damage, or 'strain', or any of the other fears that are rampant about the subject.

Any restrictions REDUCE the load on the pump. They REDUCE the wear on your pump and motor. They REDUCE the power consumption. It is the correct way to match your water flow. Get a pump marginally larger than the flow you need then "throttle it down".

The only caveat is that you must not completely BLOCK the flow. If you do the pump will eventually overheat and be damaged.

[Eric]

Just to state the obvious. Never restrict a pump on the intake side. It will cause the pump to run dry and burn up.

Eric

[kcress]

Correction; Don't restrict the suction side because it will cause destructive cavitation which will hurt the impeller. :mrgreen:

[jgreen1025]

Thank you. My thought was that it couldn't be much different than increasing the head. I've bought a ball valve and will install it today.

[kcress]

Yep exactly. Increasing head reduces the load on a pump. In some cases too little head will damage a pump's motor because this actually increases the pumps loading, though on aquarium pumps I doubt it's ever a problem.

[jgreen1025]

Thanks. I went ahead and spliced in the valve and it's working perfect now. I was able to dial down the flow enough to keep it level in the main tank. I'm afraid, however, that I widened the screen slot TOO much in an effort to handle the flow, but I'll give it a little time and see how it develops. I guess it's easy enough to make a new one if need be.

Now to see if I can get the screen to grow well and do away with the very prolific algae in the tank! :P

[new2scrub]

Hey, how do you like the quiet one pump??? i will need a pump to replace my mag9.5 soon.