Application Add 50ml of Tetra Pond AquaSafe to every 1000 litres (220 gallons) of water, to remove heavy metals and chlorine. Either treat mains water prior to using it in the pond, or treat the whole pond with AquaSafe prior to topping it up with mains water. For improving fish health and aiding wound recovery, add AquaSafe at 25ml per 1000 litres (220 gallons) every 2-3 weeks.