"Mickey" wrote in message
...
Get a smaller pump it may pay for itself in electricity.

"Tim Downie" wrote in message
...
Is is possible to use a speed controller (like a light dimmer) with a
small
pond pump?

I have a Bermuda 3000 (3000l/hr) submersible pump that's really a bit
more
powerful than I need. The motor has a solid rotor that appears to be
made
of a ferrite like material.

I know that speed controllers can cause overheating problems with some
motors but given that it's underwater with water bathing the rotor, I
don't
imagine this would be a problem in this case.


Quick calculation - 3000 l/hr pump takes 30 Watts - 1500l/hr pump takes 20
watts, so you save 10 watts switching to a smaller pump. 10 watts costs
about £5 assuming you run the pump 24*7, pumps cost £50, so you only save
money by changing the pump after 10 years!

Of course these numbers are almost certainly wrong!

I thought the best way to control the flow would be to bleed some water off
before the fountain/filter or whatever is taking too much water.

Andy