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What Can Excessive Phosphates Do to an Aquarium?

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Phosphorus forms of phosphates may be organic or inorganic in nature. Both types are generally found in aquariums, since every living thing has phosphorus in its makeup. The inorganic forms of phosphorus in phosphates, however, generally build up in your tank and lead to problems.

Signs of High Phosphates

One of the most common signs that your tank has too much phosphorus, or phosphate content, is an over abundance of algae on your tank walls and contents. Additionally, too many phosphates inhibit or prevent the calcification of coral, making it unable to absorb nutrients. This causes the coral’s skeletal system to break down and results in a lack of structural support. Eventually, too many phosphates not only make your tank look unkept but also cause destruction of your living creatures.

Testing the Water

Testing your tank every week helps ensure your phosphate levels remain within the desired limits. The key is finding an over-the-counter test that reads the levels of organic phosphates as well as inorganic. Use the recommended amount of water and follow the manufacturer’s directions when testing for phosphates. The test value should be less than 0.03 ppm, according to the Reefkeeping website aquarium water parameters.

Controlling Phosphate Level

One of the culprits of high phosphates in a fish tank is the food you feed. Commercial flakes are approximately 1 percent phosphorus, according to the Advanced Aquarist website. Phosphates are released in the fish’s waste as well. If you feed live food, either fresh or frozen, rinse it well first to help remove phosphates. Avoid over-feeding your fish. Also, since tap water generally contains a small amount phosphates, test the water you use before adding it to your aquarium.

Lowering High Phosphate Levels

After testing your tank and discovering the levels are high, take immediate action. Using a commercial protein skimmer or foam fractionator helps remove organic matter, including phosphates, from your tank. Also, growing macroalgae in your tank removes the harmful phosphates.