Probiotics  extert their best influence when used as prophylactis .They are to be used in low quantities  at regular intervals so that they can maintain optimal water quality .Higher dosages are essential to treat ponds to get the system under control followed by regularusage to maintain the system .NITRI –CHQ is a liquid probiotic blend that is capable of reducing the nitrite levels in the aquaculture operation .They are to be used in low quantities at regular interavels sothat they can maintain optimal water quality .