Anyone who has aquarium fish, be it salt or freshwater knows phosphates are a double-edged sword. Too little phosphates mean unhealthy fish, and too many phosphates mean unhealthy fish, with aquariums keeping a balance is a must.
So what are the actions of phosphates and why are they so important? Phosphates fulfill the very important task of acting as a “carrier” for energy transport within the body. The amount of phosphates the body uses is enormous. Nearly all nutrients such as proteins, fats, and carbohydrates contain phosphates, because of this a certain amount of phosphates is impossible to avoid, yet necessary for health. Even so, the phosphate level in an aquarium should never exceed 1.5%.
Excess phosphates in an aquarium can cause problems by promoting algae growth and are also detrimental to corals and anemones. Fish, especially young fish do in fact need phosphates for growth but they need it to be supplied by food, not by the water they live in as the phosphates are taken up by the digestive tract, not by the water.
There are many ways phosphates get into the water. In most cases, phosphate pollution in an aquarium is the result of overfeeding. It can also come from feeding food that contains too much phosphate already and from insufficient water changes. Phosphate levels of up to 1mg/1(ppm) can be tolerated in freshwater aquariums but in saltwater aquariums, the level should not exceed 0.1mg/1(ppm).
Your best defense against phosphate pollution is a water change when levels exceed recommended levels, and you can also use phosphate-absorbing products.
By: Rob Homer, Exotic Aquatic