You need to invest in a skimmer, either one that fits into the wall of your pond and draws about the top 2 inches of water off. The protein residue (foam) will collect in the catch trap basket and can be cleaned as necessary. Or if this method is not open to you there are skimmers available that will float on the surface and collect the foam as it moves. A bit like a Pac Man
The proteins are caused by a mixture of food, algae and the splashing fromwaterfalls, bakki showers and some pond medications can also cause it. Regular water changes and filter maintenance will help a lot to cut down on the foam.
Hope this helps 
Last edited by orca21 on Sat May 14, 2011 4:02 pm, edited 1 time in total.
I’m not shy, I’m just koi