The product neutralises ammonia and nitrite. Sera Pond Bio Nitrivec 500ml 

Highest quality filter liquid - Biofilter liquid - Contains water purifying bacteria - For crystal clear water. sera pond bio nitrivec, a product of sera biotechnology, breaks down ammonium and nitrite quickly and efficiently in a natural way thanks to the purifying bacteria it contains. The volcanic rock in the product removes harmful substances, effectively binds the turbidity and provides space for the purifying bacteria. The volcanic rock also contains calcium, potassium and magnesium - important minerals that are permanently fed into the pond. For healthy, crystal clear and biologically active pond water. Fish can be released after 24 hours of use!