Learn About Aquarium Reverse Osmosis Filters

Courtesy of Kent Marine

Image of reverse osmosis fish

Water quality in an aquarium or pond is without question the first and biggest concern for any hobbyist. Water produced from a well or local municipality can contain substances such as ammonia, nitrate, phosphate, silicate, and trace metals that can be toxic to aquatic life. KENT Marine provides reverse osmosis (R/O) and resin water purification systems to remove these harmful substances.

The most important element of a reverse osmosis filter is its membrane.

The key component for any reverse osmosis unit is its membrane. The membrane will determine the type of contaminants removed and how much water the unit will produce. TFC (Thin Film Composite) membranes will remove 95% of nitrates, up to 95% of silicates and is excellent for TDS (Total Dissolved Solids) removal. Hi-F (High Flow) membranes have the same characteristics as the TFC membrane but provide higher GPD (Gallon Per Day) water production. Hi-S (High Silicate) membranes are the gold standard and will remove 96% of nitrates and up to up to 99.5% of silicate. Chlorine will ruin TFC, Hi-F, and Hi-S membranes so prior carbon filtration is required.

Using resin as a water filtration media provides similar results to using a reverse osmosis membrane. Rather than filtering out pollutants as water passes through a membrane, resins work by attracting either positively (+) or negatively (- ) charged particles found in water. The KENT Marine Deion units and Maxxima 3 canister systems provide a final DI (Deionization) filter step using mixed bed resins. One drawback is that resin does exhaust and will need to be replaced or regenerated more frequently to maintain high quality water production.

Reverse osmosis water has disadvantages. While it is clear of toxins, it is stripped of good water minerals and elements that must be manually replaced.

There are some disadvantages to Reverse Osmosis water. While you are assured that the water contains negligible quantities of the problem and toxic elements, it is also stripped of all "good" minerals and trace elements needed by fish and plants for a healthy habitat.

Most aquarium salt mixtures are designed to replace the missing trace elements and minerals. However, freshwater hobbyists must test and then replenish the elements one at a time.

Don't let this discourage you. Reverse Osmosis water is often the only option (or only cost-effective option) to prevent poor water quality. All of the water changes and maintenance in the world will not keep your tank inhabitants healthy if you put polluted water into the tank every time you top it off.