Does your water look murky? Br is it green or brownish in colour rather than clear? Br if so then crystalwater treatment from tetra could be just what you are looking for. This treatment binds together suspended pond particles which causes them to sink...

Effective intensive pond treatment for treating all common algae types including blanketweed, floating algae and smear algae. Br algofin works by attacking the ability of the algae to photosynthesise and grow.

Use when mouth and fins appear to be rotting away white cotton wool like growths are visible on the fish the fish flick against solid objects fish gasp at the surface appear to be covered in slime or white spots.