It is said that water treatment chemistry is getting too complicated and trying to understand its complications are becoming ‘nightmare on Elm Street’. In swimming pools, Koi ponds, Natural ponds, lakes & rivers eutrophical production of any environmental control favours plant life over animal life.


With increasing applications of ‘biodegradable detergents’ poured down the waterways of the country our ‘green’ additives are not true green at all. Too many manufactures of cleaning compounds are adding far too much Phosphate based chemicals. Thames Water some time back tested levels at 500 times their natural levels. Now days it is common to get up to 500ppm/mgt through the kitchen tap, which is a good turn on to algael growth.


In September this year an algae manifestation in St Ives Devon killed several thousand coastal fish. Phosphates have had a love affair with algae for donkey years and the warmer the water the quicker algae grow. Phosphates are found naturally in the earth; in mixes of fertilisers, in water ‘softening’ devices that use compounds containing Calgon (Sodium Hexameta Phosphate).


The chemical is not dangerous. They are an irritant, whilst their inhalation, ingestion and contact with skin & eyes should be avoided. In arable land fertiliser used in the UK the cheapest quality compounds are usually applied which take years to saturate deep into the earth in aquafils, deep underground water channels that feed into sources for bore hole applications. In domestic home applications a higher grade of Sodium Meta Phosphate is used for water devices and not recommended for using in swimming pools. In commercial softening the use of the compound is much larger.


The Water & Waste publication (WWT) way back in 1989 quoted Anglian Water contributing a minimum of at least 50% of Phosphates from the detergent manufacturing giants. Too many ‘fully biodegradable’ or ‘Phosphate free’ statements are often made to defend their ‘green status’. Phosphates are now a big problem in the control of algae.


They cause grief in swimming pools. They cause acute blanket weed build up in Koi ponds sometimes clogging up circulation pumps. They can increase bacterial problems in Natural ponds – in fact in mid summer this year blue – green algae called loosely ‘Cyano-Bacteria’ poisoned a collie dog after an afternoon swim at Petworth Park in Hampshire


How to remove Phosphates. Phosphorus is an organic compound.

1. From above ground & in ground swimming pools & spas apply in liquid or slurry format or in ‘gel block’ format.

2. From fish ponds, Natural ponds and lakes apply in liquid or slurry format, gel block format can be used in some applications. The material can be extracted by both sand & cartridge element filters but not by Diatomaceous or Perlite earth filters.

3. From in ground swimming pools, fish ponds, Natural ponds & lakes in hard water areas only. Install a non-electrical rare earth permanent magnetic conditioner in water flow lines. This will prevent blanket weed (an algae) sticking to butyl, fibre glass & concrete surfaces and prevents Calcium Carbonate (scale, chalk, limestone) building up on the inside of U.V. steriliser tubes, gas & air to water heat pumps.

Remember Calcium Carbonate builds up in both cold & hot water temperatures & helps to stabilise both pH & Total Alkalinity. Refrain on the use of compounds that contain Phosphates. Magnetic conditioners have no effect in soft water conditions