<a href=showthread.php?s=&postid=9391834#post9391834 target=_blank>Originally posted</a> by crumbletop
Yes, I'm pretty sure you can make a 7 a 5 by just changing the impeller. I don't know where to get one locally, though.
I actually read somewhere that its better for a pump to be throttled down. I read it when i was looking into buying a pump a while back. I believe it was the mag 7 that i was looking at when i read this. after reading this i planned to go to a larger pump and then throtleing it down to save some stress on the pump but ill have to read some more to see if this is true.<a href=showthread.php?s=&postid=9392230#post9392230 target=_blank>Originally posted</a> by DMBillies
I don't like throttling pumps back very much because of the stress it puts on them.
gotcha. just thought id let you know.<a href=showthread.php?s=&postid=9395869#post9395869 target=_blank>Originally posted</a> by DMBillies
Ok, so perhaps I'm wrong about the throttling it back causing stress. I've read that in places before, whether it's right or wrong. In any case, the pump gets louder when I throttle it back any more, which is a no-go for an office tank.
thanks for that info c__stowers. That makes alot of sense. It took me a little thinking to figure out where exactly the T goes but i figured it out. Its to early to use my head lol.<a href=showthread.php?s=&postid=9404709#post9404709 target=_blank>Originally posted</a> by c_stowers
Throttling pumps back to increase the efficiency/longevity of the pump depends on the pump curve for the specific pump. Unfortunately, most data for aquarium pumps don't include motor efficiencies and NPSHR (Net positive suction pressure required) and many other useful parameters for choosing the correct pump for your application. If you don't want the noise, but want to reduce the flow, you can always put a "T" then a ball valve and divert some flow back to the suction side. This does not put additional head pressure on the pump, but can sometimes be difficult to plumb (depending on your system).