I am relatively new to having fish ponds, as I inherited two ponds when I moved into my current home. (One is natural looking pond with one koi in it and the other pond has a decorative fountain and about 21 goldfish in it.) At the moment, I am feeling frustrated with the goldfish pond (approximately 250 gallons, fountain spills over into pond that the fish are in). Maybe a month ago, my husband cleaned the whole thing out. I then dropped Jungle Pond Block and Jungle Pond Clear in the amounts according to the package instructions, added a bit of blue pond dye, put in chlorine remover when we added the water back in, and replaced the previous pump and filter with what seemed like a better one. (There's actually two pumps, but one just circulates water in the fountain.) I have been continuing to use the various products at the recommended intervals. We already have green showing up again - on the bowl of the fountain, on the side walls of the pond - and my husbands says that he pulled one of the rocks out from the bottom and said it feels slimy. What can we do? Thanks in advance!