Shredder Pump No Load power consumption query

[www.GymRatZ.co.uk]

Any thoughts on the following scenario:

Pond pumps are great but at the moment they're regularly blocked with leaves so I got to thinking about dirty water "shredder" type pumps that will mince up any leaves, frogs etc that find their way into the pump sump.

There were 2 thoughts that came to mind.

First was if the motor is quoted as 500W would the low-load consumption be significantly less i.e. if it was just pumping clean water to a head of around 2 foot compared to under maximum load if it was shredding lots of solid waste or would the 500w be a fairly static consumption balanced by increased pumped volume of liquid compared to low volume maximum head?

The other thought was, although these type of pumps are not designed with a 100% duty cycle in mind, if operated continuously submerged in "clean" (apart from the occasional willow tree leaf) cold water why shouldn't they sustain a 100% duty cycle? It's got to be less of a strain than chomping up turds and toilet paper on/off 50 times a day?

Cheers - Pete

[Brian Gaff (Sofa]

My feeling here is that you do not want to be putting any wildlife such as insects, lavvy, and the fish fry through it, This is why pumps have narrow filters.

What you might try is an outer filter, say made of chicken wire surrounding the pump intake and this hopefully will catch the leaves and is easily removed to clean it without the need to bring up the pump filter every time. Of cours you may want a sterile pond, that is your decision. Brian