Interpet Bio-Start contains biological cultures for the rapid colonisation of a new filter. To help keep your pond crystal clear, use Bio-Start to prime your filtration system and whenever new fish are added. Use Bio Start whether you have a filter or not. To establish a new pond. In spring to kick start the pond out of its dormant state. After using medications, which may have damaged biological cycles. If test kits indicate high levels of toxic waste. Each sachet treats up to 500 gallons of pond water. Simply add to filter or pond. Carton containing 4 sachets to treat up to 2000 gallons (9000 litres). Value carton contains 20 sachets to treat up to 10000 gallons (45000 litres). Pack treat up to 2000 gallons (9000 litres).