Ultra violet light systems

Medium pressure lamp ultra violet (UV) light systems reduce chloramine concentrations significantly. Recent evidence suggests that UV light systems, besides providing additional disinfection, also inactivates chlorine resistant micro-organisms such as the parasitic protozoans Cryptosporidium parvum and Giardia lamblia. Because UV light does not impart a residual disinfectant to the pool water chlorine must still be used at recommended concentrations.

Ozone

Ozone may be used to control chloramines and has good disinfection properties. Ozone may be used in addition to, but not instead of, chlorination. Pools utilising ozone must quench the ozone using a granular activated carbon filter before the water is returned to the pool. The exception is the use of low dose ozone (up to 2g/hour) where the ozone is pumped with air through a venturi into a mixing chamber and reaction vessel in the circulation system after the pool water has been filtered. Provided the ozone is thoroughly mixed and dissolved, it reacts rapidly to destroy chloramines and disinfection by-products to reduce tastes, odours and eye stinging compounds.

From a fact sheet isssued by the Government of New South Wales, Australia.

Note: A combination of UV and Ozone, or copper-silver ionisation with chlorine production, or chlorine production with ozone can greatly reduce the amount of chlorine needed.