Lincs Fish Health Pond Detox.
Pond Detox Formula will reduce the levels of many pollutants in the pond
When pollutants are at high levels such as Copper, Lead, Zinc, Ammonia, Nitrite & Acid Rain they are liable to cause your fish to die.
At low levels pollutants make fish more susceptible to disease. 
Pond Detox Formula neutralises pollution, improves water clarity, settles particles, enriches skin colour, improves skin lustre, aids digestion and generally improves health.