hi, i am having an impossible time with my pond. brown water and the skimmer is filled with muck 2 times a day. 4000 gallon pond with a 5,000 gal pump going to a pool type filter that then goes into a hydramax filter with a 37 watt uv light. also a 10,000 gal pump to the little giant waterfall with 2 pads and bio balls. i also have a large bubbler in the 6' end. i was adding barley extract now i have 2lbs of barley straw. i have made 8 - 1000 gallon water changes in the last 4 weeks. i have been adding 4 ounces of clay a week for 8 weeks. any suggestions????? bill

The brown color and foam are dissolved organics, the consequence of a closed biome accumulating products of plant and animal metabolism and decay. Adding stuff won't help, and may make some of the problems worse. Most of the brown color is phytocyanin, a breakdown product of chlorophyll, and the source is your barley straw!

Water changes will help. Getting the barley straw out of the system will help. What you really need though, is an efficient protein fractionator. Talk to Mike White (www.whitewaterfilters.com).

(Answer courtesy Bob Passovoy)