Aluminum Sulfate FREE Sample
Pure Alum/Aluminum Sulfate. 40 lb.-60 lb. Per Acre Foot Aluminum Sulfate (Alum). Alum is the most effective treatment for clearing muddy water caused by colloidal clays. Application rates for alum are recommended at 25 to 50 pounds per acre-foot of water depending upon the concentration of suspended clay particles. The first treatment should be made at the rate of 25 pounds per acre-foot. Clay particles should settle and the water should clear within a few hours after mixing the alum. If there is little noticeable change after one day, then a second application should be made at 25 pounds per acre-foot. Alum should be applied during calm weather to avoid wind mixing that prevents clay from settling out. It is most effective when dissolved in clear water and sprayed over the surface from shore or a boat. In large ponds, a dissolved solution of alum can be poured into the outboard motor wash of a small boat.
Alum can reduce the pH and alkalinity of pond water due to a strongly acidic reaction in water. For this reason, pH and alkalinity need to be tested before treatment with alum to prevent harmful effects to fish. Alkalinity should not be below 75 mg/l and pH should not be below 7.0. If readings are found to be below these levels, then hydrated lime should be added in the same manner as alum at the rate of 50 pounds per surface acre. This will help buffer the acidic effects of alum treatment and protect fish. Alum is only toxic to fish under these conditions or when used at very high concentrations for a long period of time.