hotpepper wrote:

Forgot to say - got back from work today after being away for a few
days and hence not been messing with the pond. The water is crystal
clear all the way to the bottom. I can see all the fish which has put
me at ease, the Orfe are darting around like mad and the tench are
slowly moving around the bottom - one even came to the top to eat! I
can now see the shape and layout of the pond so probably wont drain and
clean it.

I switch of the pump while cleaning it and for some reason sediment
started to stir up, is this normal? Why does this happen?

I'd guess your pump is moving water to some point above the water level of
the pond. When you switch it off, all the water in the pipe runs back down
into the pond, through the intake - which one assumes is near the bottom of
the pond - and stirs up the remaining sediment.

If there's any chance at all that the pipe could spring a leak that would
cause water to leave the pond, you should try to raise that intake up a few
inches, so that a catastrophe still leaves enough water in the pond for
your fish to survive!
--
derek