Dialing down return pump

I put a ball valve on my Eheim 1260 return to help with a small microbubble problem. My question is, how much can you turn it down before it affects the lifespan of the pump? I don't want to damage the pump by dialing it down too much. Thanks.

 

One may ask what the source of those bubbles entering the return pump are? If those are eliminated then that will solve your problem right there.
I wonder if restricting flow too much may ultimately cause some cavitation, in addition to more wear and noise?

 

It does not hurt a centrifugal pump at all to valve them down on the discharge side. You can easily cut the flow in half and it will not have an effect on its lifespan. On many pumps it actually makes them more efficient and could extend their life since it is doing less work.

Cavitation would be acused by valving the suction side not the discharge side. Valving the discharge is essentially the same as adding head or additional height to the return line. Higher head equals less water pumped or less work so results in lower power consumption or watts used.

 

Thanks much--gives me some peace of mind! I'm still going to come up with some ways to cut down on bubbles with other methods.

 

I’m curious as to why both my reactors Maxijet 1200 and my much larger Quiet One return internal’s will start to chatter when there is too much resistance/throttled back too much.

 

i know it doesnt make sense some times lol.. why more head pressure means less wattage on many pumps but it does i even checked with a killowatt meter...
my family makes fun of me because im notorious for being a killowatt junkee..

 

I solved the problem almost entirely by adding a third baffle to my sump. It was a pain, and I didn't let it cure completely because I had a fuge with algae and pods I had to worry about, but the bubbles are pretty much completely gone. I knew I should have went with three baffles to begin with!