I have had the same problem, my pond is 4,000 Gallons and I have 10 carp with all but two being less than 10" and the bigger ones about 15". I put my UV back in the system again and started using barley straw pellets. The weed has nearly all gone from the base of the pond and is breaking up on the walls nicely.
I have also installed a vegetable filter with the hope that phosphate levels are reduced and will be able to tell later on in summer if this is working.
Pond clear isnt the cheapest but works, however you need to keep using it to keep the blanket weed away
Good luck
Posted on Apr 3, 2006, 1:22 PM from IP address 82.34.105.127