Click to expand Tap to zoom King British Safe Water Filter Aid 250ml Save Liquid error (product-badge line 32): -Infinity% £8.48 1 2 3 4 5 6 7 8 9 10+ Quantity Quantity Add to cart King British Safe Water No.1 Degrades ammonia and nitrates that are harmful to fish. Boosts the processing power of biological filters. Suitable for tropical and coldwater fish. 250ml