Like a good aquarist you feed your fish daily and give them the most nutritional foods available. However as this highly nutritious food is digested by our fish phosphate is eventually released into the aquarium. Although this is not the only source, tap water and even bottled water can contain levels of phosphate considered to be high by hobby standards.
 
  1.  Phosphate chemically referred to as P04 is a chemical compound released from food after it has been digested or broken down by other means. Inorganic phosphate is the main form of phosphate tested for in the marine aquarium hobby.

2. The main cause for concern of phosphate in the marine aquarium is its effect upon all types of corals, but specifically LPS and SPS corals. Phosphate at levels above 0.03 mg/L (milligrams per liter) are known to prevent calcification, or the rate at which corals are capable of assimilating calcium and building up there skeletons.

3.  If phosphate is above 0.10 mg/L. This should be immediately addressed. A liquid phosphate such as Liquid Phosblaster will quickly remove any phosphate and precipitate it out of the aquarium water. If your phosphate is lower then .10 mg/L then a granulated ferric oxide media is the product of choice. However this media can be used in a media bag but is best used in a reactor.

Liquid Phosblaster Dosing

Calculator


Further information can be found at

http://reefkeeping.com/issues/2004-11/rhf/index.php