Wouldn't think you would need to change the water unless it tests really
bad. I haven't changed mine in thirty years although the pond has turned
green several times when the pump failed. A good filter will clear it up if
it is big enough. The fish won't mind muddy or algae water; they seem to
enjoy it more....



"Granny" wrote in message
oups.com...
I moved into a house last year and the previous owner had taken his
water pump, filter etc.
There is a higher pond which should feed into the lower one but both
are now quite murky.

The fish and frogs still seem quite happy but the water needs cleaning.
I have tried the tablets but limited results.

I am going to install a pump and filter but want to know whether I
should empty most of the water first and refresh with clean water in
order to not clog the filter when it's initially set up.

I would appreciate any advice on this since, at the moment, I can't
afford to pay someone to do it for me.