The 6 Best Phosphate (PO4) Removing Products, According to a Veterinarian

Phosphate itself is not harmful to fish, but it will significantly boost your algae load. Most of the time, algae is an aesthetic nuisance, but at high levels, it can choke your corals and suck all the oxygen out of your water. Algae uses both phosphate and nitrate as a food source, so be sure to check your levels regularly and keep up with your regular maintenance to limit your supply on other remedies.

There are a few products available that remove nitrates and phosphates, but in doing double duty, a product’s potency is reduced. There are different mechanisms for removing phosphate and nitrate from your system and often, one will work better for one product than the other. If you are having continual issues with both your nitrate and phosphate, take a close look at your maintenance regimen and fishes’ diet before dumping something else into your system for a quick fix.

Protein skimmers do not remove phosphates. Phosphate reactors look very similar to protein skimmers but utilize GFO media in order to be effective. Bubbling air through water containing phosphates, such as a protein skimmer does to remove proteinaceous material, does nothing to remove phosphate.

Phosphate remover does not kill algae directly but takes away their food source. Algae utilizes phosphate and nitrate produced by your fish and their environment to grow and flourish. If you remove these with your regular maintenance, minimize food waste and add a phosphate binder. Most phosphate binders can be used temporarily to take care of spikes until you get back to your normal routine. In the rare case your source water is high in phosphates, you may need to use a phosphate-binder long term with severe algae issues.

If you notice your algae getting out of control, it makes sense to invest in a phosphate test kit. Some freshwater test kits may include a phosphate test kit, but not many. Many inexpensive, liquid-based kits are available in specialty pet stores and online. Keep in mind that some products may test positive for bound components, such as those created with liquid products, until the precipitate is physically removed from the system.

If you are using a phosphate remover, you should see a reduction in your algae load within the first few days. You may see cloudy water as phosphate is bound into an insoluble compound that will need to settle out of your water. Using your test kit, you should appreciate a drop in phosphate levels. If you do not see results, read your instructions carefully. If you are not using a liquid product, be sure to have your media in an area of high water flow in order for it to come in contact with more of your tank’s water.