Regulate Nitrates & Phosphates in Your Reef Aquarium

Nitrates, polyatomic ions, and phosphates, polyatomic anions, represent two powerful eutrophicants (a process by which nutrients, in this case pollutants, accumulate in an environment) for your reef aquarium. Nitrates develop during the final phase of the nitrogen cycle (resulting from nitrogen nitrification). Phosphates are chemical compounds consisting of “phosphorus” and “oxygen” ions (PO4), present in almost all living marine organisms. They are therefore primarily expelled as biological waste by the inhabitants of your tank.

Nitrates (NO3)

Phosphates (PO4)

Where do they come from?

As explained in the paragraph above, the sources of nitrate and phosphate input in your reef aquarium can be numerous. Here is a list of best practices to adopt to reduce NO3/PO4 levels in your tank.

Make sure you have good quality RO water. Don’t hesitate to test the NO3/PO4 levels of your RO water directly. Tip: Also test its silicate content. If present in too high a concentration, silicate can lead to the appearance of unwanted algae.
Change approximately 10% of your water every two weeks. Water changes are very important because they allow your tank to maintain a balanced level of essential elements (Calcium/Magnesium/Carbonates…) and reduce nitrates and phosphates at the same time.
Clean your filter media regularly. Filter floss and other filter media are very effective at capturing particles and waste from your water. However, don’t forget to clean and replace them regularly, as they represent true “nests” for Nitrates and Phosphates. The recommended cleaning frequency for filter floss is approximately every 12 days, and ideally it should be replaced every 3-4 cleanings, depending on the brand and quality.
Install a protein skimmer suitable for your tank. Although some reef aquarists using alternative methods are not fans of protein skimmers, it is still highly recommended to install one, especially if the NO3/PO4 levels in your reef aquarium are above recommended levels. Powerful skimming of your tank will allow you to eliminate organic matter before it enters the nitrogen cycle, which leads to nitrate production. Tip: Don’t rely on manufacturers’ skimming volume specifications; do your research beforehand to choose a quality skimmer.
Adjust feeding according to your population. One of the main causes of excessively high nitrate and phosphate levels is food. It is essential to choose quality food and not to “overfeed” your tank. Opt for frozen and fresh food rather than flake food. Pellets are a good compromise for aquarists who don’t have the time. It is recommended to feed your fish and crustaceans multiple times; this prevents food from ending up at the bottom of the aquarium or in the filtration.
Provide sufficient water flow in your aquarium. Water flow in a reef aquarium is very important and should absolutely not be neglected. It is recommended to circulate between 30 and 40 times your tank volume per hour. Be careful to distribute the flow evenly throughout all areas of your aquarium.
Maintain your sand properly. If you have sand in your aquarium, it is essential to stir and turn it regularly so that it doesn’t trap too much organic matter. For this, it is recommended to add detritivores, such as “Nassarius” sand snails or a sand urchin “Clypeaster”.

Too many nitrates and phosphates in your aquarium? What are the risks?

The Nitrate level in a reef aquarium should ideally be between 2 mg/L and 15 mg/L, and the Phosphate level between 0.01 mg/L and 0.10 mg/L, depending on the tank population and type of corals.

Having nitrate and phosphate levels higher than those recommended above can lead to negative consequences for your reef aquarium and its inhabitants. Here are the four main problems encountered when NO3 and PO4 levels are too high:

Appearance and development of unwanted algae. Nitrates represent an excellent nutritional source for algae in reef aquariums. A concentration above recommendations will lead to overfeeding of unwanted algae and consequently, rapid growth. Once present in a reef aquarium with a high nitrate level, they will quickly become overwhelming, which is then called “proliferation”.
Slowed coral growth. An excessively high NO3/PO4 level stimulates the expansion of zooxanthellae, a unicellular algae that, at high concentrations, causes a decrease in coral growth. Indeed, excessive development of zooxanthellae inhibits coral calcification and deprives them of inorganic carbon, necessary for their development.
Coral discoloration, bleaching, and necrosis. Although some soft corals tolerate a relatively high NO3/PO4 level, this is not the case for all. Indeed, certain corals, such as calcifiers, need an environment low in nitrates and phosphates. The two main risks are discoloration and RTN. Rapid tissue necrosis (RTN) is a highly contagious disease in which coral tissue detaches from the coral skeleton.
Affect the immune system and health of marine inhabitants. Certain marine inhabitants of a reef aquarium, such as invertebrates and SPS/LPS, have very low tolerance to nitrates and phosphates. They can be negatively affected by short- and medium-term exposure. Additionally, almost all inhabitants of a reef tank, including fish, suffer serious consequences when exposed to high NO3/PO4 levels over the long term. The main problem fish encounter is physiological: nitrates and phosphates cause a drop in antibody production, damage the kidneys, affect blood composition, and also affect osmoregulation (the ability of fish to regulate internal fluids).

How to eliminate nitrates and phosphates from your reef aquarium?

NO3/PO4 Symbio® is a product composed of a unique formula of 5 marine bacterial strains, combined with a set of bio-enzymes and organic carbon, specially selected for their ability to eliminate nitrates and phosphates present in your reef aquarium. By transforming them into biomass, an optimal nutritional source for corals, sponges, microphagous filter-feeding animals, as well as for the development of microfauna and macrofauna, NO3/PO4 Symbio® provides an effective, natural, and fast solution to regulate nitrate and phosphate levels in your reef aquarium.