Seachem Phosguard

[AquaticExpressions]

The reason that Phosguard recommends it to potentially removed within 3 days because of how fast the product works in efficiently removing phosphates. Once the phophates have been removed then you add new phosguard to ensure phosphates don't climb. Phosguard is a spherical Aluminum Oxide. Aluminum oxide is an insoluble form or aluminum. At the pH most hobbyist keep reef tanks, release of aluminum is not an iue for corals. Aluminum oxide is not easily absorbed into the cell to cause negative reactions. Even at three times the dose of PhosGuard, oft bodied corals such as Sarcophyton, do very well with more than the recommended dosage of PhosGuard.

The removal of phosphate isn't low or gradual when using PhosGuard, so the quick change can show negative impact that is temporary also it is not rechargeable.