NT Labs Koi Care Filter Bugs 250ml - 1000ml Concentrated Essential Filter Bacteria When to useUse when establishing a new filter, at the beginning of the pond season in spring, or when ammonia or nitrite are elevated. Filter Bugs is an easy-to use liquid formulation, containing a blend of Nitrosomonas, Nitrobacter, Nitrospira and supporting bacterial cultures. These bacteria will repopulate your filter with nitrifying organisms to ensure efficient biological filtration and perfect, stable water quality. Do...Test your water using Pondlab Test Kits. Measure out the required amount of Filter Bugs and add directly to the biological media within the filter. Switch off UV filtration for at least 24 hours after adding Filter Bugs to allow the nitrifying bacteria to colonise the filter and the pond. Filter Bugs should be added immediately after a substantial water change or pond clean, at the beginning of the pond season, after using a medicinal treatment or adding new fish, and whenever there is a detectable concentration of ammonia or nitrite in the water. Filter Bugs can be added once per week, or more often if desired. Filter Bugs can be used when Pond Salt Plus is present in the water at ‘General Tonic’ and ‘Anti-stress’ levels. WarningAmmonia and nitrite are toxic to fish. Their concentrations should be 0 ppm at all times and can be tested accurately using Pondlab Test Kits. If ammonia and nitrite are present at dangerous concentrations, carry out a partial water change before using Filter Bugs. Ensure the cause of poor water quality is identified (e.g. over-feeding, insufficient aeration, etc) and resolved to avoid causing stress to your fish.Available in three sizes250ml - treats 9100L500ml - treats 18200L1000ml - treats 36400L Dosage10 ml → 80 gallons (364 litres)