Water regulating disease preventing biological medium used for freshwater aquaculture animal fry culture

The invention is a water regulating disease preventing biological medium used for freshwater aquaculture animal fry culture. The water regulating disease preventing biological medium consists of fermented soybean meal, sugarcane molasses, wheat bran, lactic acid bacteria, saccharomycetes, monopotassium phosphate, monocalcium phosphate, magnesium sulfate and sodium chloride, wherein lactic acid bacteria are obtained by mixing lactobacillus plantarum with bacillus coagulans. By regular use of the biological medium disclosed by the invention, beneficial bacteria communities including ammonifyingbacteria, nitrite bacteria, nitrifying bacteria, denitrifying bacteria and the like can be gradually cultivated in a water body; the biological medium has stable and efficient ''denitriding'' ability,has both an assimilation function and a dissimilation function (making waste nitrogen in the water leave the water body in the form of nitrogen), purifies the water body and stabilizes the system. Inaddition, beneficial micro