Traditionally water softeners were used to treat boiler make-up water, but now reverse osmosis has become an economically viable alternative.

The advantages of reverse osmosis over a water softener include:

• A reverse osmosis plant removes more than just the Calcium & Magnesium Hardness, so the water is far more pure
• 90 to 99.9% of dissolved solids are removed which allows much higher cycles of concentration & far less blowdown
• Reduced boiler fuel usage & fuel costs
• Reduced boiler make-up water consumption
• Far less internal boiler water treatment chemicals are required, which reduces chemical costs
• Make-up water alkalinity is reduced, which reduces carbon dioxide dissolving in condensate & forming highly corrosive carbonic acid; so neutralising or filming amine chemical costs are dramatically reduced 
• Reverse osmosis removes silica from the make-up water which can form one of the worst types of boiler scale & significantly reduce boiler efficiency  
• Boiler heat transfer surfaces are much cleaner & efficient
• Reduced boiler cleaning costs & elimination of acid cleans
• Increased boiler reliability & elimination of costly unscheduled shutdowns & down time 
• The reverse osmosis plant reject water may be suitable for use as cooling tower make-up water or wash down water. Water softener waste water is not suitable for these uses
• Sodium Chloride is not required for resin regeneration
• The need to buy, store & manually lift heavy 25 KG bags of salt is eliminated 
• Better steam purity