For users who require very high levels of purity from their recirculating water, ATC can offer an in-line deionizer, with all necessary fittings, mounted to the rear of the chiller. This will polish the recirculating water to better than 1 to 10 Siemens/cm. Cartridge expiry indication is by means of colour change windows (blue - ok, brown - replace). A by-pass flow system is included to ensure that the flow rate through the cartridge is always optimal.