Reverse Osmosis

Reverse Osmosis systems purify water by forcing it through a semi-permeable membrane. It’s a simple process, and one that’s been around for hundreds of years. In fact goat herders in the deserts of the middle east would put brackish water into goats bladders and the water dripping out the other side would be pure and drinkable.

Today’s reverse osmosis systems use a membrane  called poly-amide (PA) membrane. Filtering water at around 0.0005 microns, so fine that it can strain salt out of the water.

Reverse Osmosis water is used in a number of commercial applications, did you know it’s the water the car wash uses for the spot free rinse? It’s also used widely in the food industry.

Many reef aquarium keepers use reverse osmosis systems for their artificial mixture of seawater. Ordinary tap water can often contain excessive chlorine, chloramines, copper, nitrogen, phosphates, silicates, or many other chemicals detrimental to the sensitive organisms in a reef environment. Contaminants such as nitrogen compounds and phosphates can lead to excessive, and unwanted, algae growth. An effective combination of both reverse osmosis and de-ionization (RO/DI) is the most popular among reef aquarium keepers, and is preferred above other water purification processes due to the low cost of ownership and minimal operating costs. Where chlorine and chloramines are found in the water, carbon filtration is needed before the membrane, as the common residential membrane used by reef keepers does not cope with these compounds.

Household reverse osmosis units use a lot of water because they have low back pressure. As a result, they recover only 5 to 15 percent of the water entering the system. The remainder is discharged as waste water. Because waste water carries with it the rejected contaminants, methods to recover this water are not practical for household systems. Waste-water is typically connected to the house drains and will add to the load on the household septic system. An RO unit delivering 20 Litres  of treated water per day may discharge 200  to 400 Litres of waste water per day.

Talk to us about your options for this type of system.