What do RO and RO/DI units do?
- The TFC membrane removes calcium and magnesium (which make up general hardness, GH) and any carbonates (that make up the carbonate hardness, KH). This leaves you with truly soft water.
- The Sediment pre-filter is a fine (1 or 5 micron) mechanical filter to trap large particles in the water, and some bacteria.
- The Carbon pre-filter removes large particulate waste and chlorine in the water. This is especially important with TFC membranes, as the chlorine will degrade their performance.
- The Deionization (DI) cartridge found in RO/DI units removes some other chemical compounds often found in the water--primarily nitrates, phosphates and silicates.
How do RO Systems work?
The RO TFC membrane operates as a semi-permeable membrane that is placed under pressure (from the water supply) to cause water to pass through the membrane in a Reverse Osmosis direction, producing pure, soft water.
What are the RO System maintenance costs?
The sediment pre-filter, the carbon cartridges and the Deionization (DI) cartridge will need to be replaced after about 6 months or approximately 1000 gallons of RO water produced, depending on local water conditions. The RO membrane should be good for approximately 3 years.
What types of aquariums should use RO water?
All aquariums should use RO water because tap water contains many impurities. These impurities include phosphate and nitrates, which fuel algae growth. Copper--highly toxic to invertebrates--can be leached from household pipes.
What needs to be added to RO water?
Because an RO system will remove almost everything from the water, you will need to add back in some essential minerals. Marine aquarium salt mixes all contain these essential minerals. For freshwater use, you need to add back electrolytes, as the RO water will be too pure for the fish or plants. You will also need to add some type of buffer to prevent wild fluctuations in the pH value.