I know that Kelly, Ted and others will shudder, but if you go to Home Depot and get a few 1 lb boxes of Zep septic tank enzyme and bacteria at $4 per 1 lb container, put in 2 lb per acre, 2 wks later 2 lbs., and taper to 1 lb then 1/2 in 2 wk increments(for total of 12 wks), it will add lots of beneficial enzyme producing bacteria, or you can not have Christmas and go with the special concoctions sold especially for ponds. Just my opinion after much research and inconclusive evidence of the contents of the expensive products.