If you could have a veggie filter pond, as suggested in the urn option, you
would cut the nutrients to your algae and need less cleaning. Nine large
goldfish in 250 mgallons is a heavy load.

Too bad you don't have a larger pond (the urge hits lots of us) that could
handle koi, who would eat your string algae.

Good luck

--
See our pond at: home.bellsouth.net/personalpages/pwp-jameshurley
Ask me about Jog A Thon fundraiser (clears $120+ per child) at: jogathon.net
wrote in message
oups.com...
I have a pond in my yard probably 250 gallons. It has 9 big gold fish
in it from the previous owner. Without fail every year about this time,
I've been told due to heat and sunshine, the pond gets really nasty.
What should I use to keep it clear and clean?