the type of filter you need depends on whether it is green water or blanket
weed. But best to sort out why there is a change if your old filter used to
work ( I hate selling equipment when its not needed)

Check these first.
If your filter worked previously and you have cleaned it out recently it may
need new bacteria to start it up again.
Blagdon bio start would be useful if this is the case.

You may have too many fish ( you do not give the surface area, so I can not
say) and so have increased the ammonia and nitrates which will in turn
increase algae growth (usual rule of thumb, 1inch fish to every sq foot of
water)

With the weather being so hot a lot of ponds have too much sun . Try
covering over the water to add some shade and increasing you plant cover.

If you do need a filter our best seller is the hoselock bioforce check
details on www.arghamvillage.co.uk it is a small compact unit and can be
buried so no ugly black box.

If the water has no large particles but is green you will need a UV
clarifier, or combined filter, these make the particles stick together so
the filter can remove them.

if its blanket weed then you will need a magnetic clarifier or try blagdons
new blanket weed filter.

you can use treatments such as the Blagdon pondsafe range to clear the
water. this may be cost effective if the problem is only during hot weather.

Tell me more of your problem and I will be glad to give you more detailed
advice.

NoSpam wrote in message
...
Hello All,

I have a Gold Fish pond that is about 2500 gallons. There are about 20 to
24
good sized (4 to 5 inches long) Gold Fish in it. The problem that I'm
having
this year is extreme algae. I have a home made filter that until this year
did a pretty good job of keeping the water clear.

So I want to buy a commercial pond filter but don't know what to buy. Can
anyone give me some suggestions as to the type of filter that would be
best
for a fish pond as well as the size for 2500 gallons.

Thanks

Brian