Don't Fear Phosphate, You May Not Have Enough!

Let's talk about phosphate. For decades the culture in aquarium keeping vilified phosphate as a fuel for algae without any mitigating merit. Over the years, aquarists have spent a massive amount of effort (and money) on removing it entirely from the water of their aquariums. This thought process was not wholly unjustified, when phosphate levels are too high, and/or out of proportion with other available nutrients like nitrate, it can be a primary driver for nuisance algae growth in our aquariums.

The downside of the zealous nature of our obsession with removing phosphate, is that it is a nutrient that corals need to build skeletons and display their beautiful colors. Removal of it completely left many a frustrated aquarist with poor coral growth rates and generally brown corals. As an aside, keeping your corals colorful is a puzzle with many different pieces that are beyond the scope of our discussion today, but having some phosphate available in the right formulation is part of it. Most phosphate arrives in aquariums as by product in the foods feed our aquariums, and the waste produced by the animals eating this food. Some also dissolves naturally from live rock and aragonite sand. Some phosphate is introduced with water changes if there is some phosphate in your water supply, which is not uncommon. Controlling this soluble phosphate is still an important part of keeping your aquarium healthy and keeping algae growth within acceptable levels and we have other articles here on the website to delve into products and techniques for controlling out of balance (and out of control) phosphate levels. All this being said, practices like carbon dosing have the possibility of removing too much phosphate, leaving nearly nothing behind. Newer aquascaping practices like bare bottom tanks and faux rocks can result in not enough phosphate being available to the bacterial colonies and corals that need it.

The natural nutrient supply mechanisms on coral reefs have inspired the line of Tropic Marin Phosphate supply products. The insoluble particulates in the secretions of fish and other marine animals supply phosphate and all the other necessary substances responsible for the microbiology that coral growth and coloration are dependent on. There two such products, utilizing these principles, available to the home reef aquarist.

The first is Tropic Marin Phos-Start. It can be used on fish only and fish only with live rock tanks, where it will stimulate good bacterial colonies and support coralline algae growth. The best aquarium type for this product is a reef tank, and stony coral tanks in particular. In these tanks there is often a low supply of organic bacterial food and nutrients, Tropic Marin Phos-Start will fill these gaps to prepare the aquarium to support and grow robust and colorful corals. It will supply non-soluble phosphate as well as bacterial food, all as fine particulate. This allows the phosphate and other nutrients to be easily filtered out a used by the coral while hindering the availability to algae that proliferate on soluble nutrients. This results in stronger, healthier, more colorful corals that grow better and display more natural forms.

Phos-Start is formulated for use only in the first two to three months after setting up an aquarium and is especially beneficial during cycling; it is a great addition for hobbyists who are also utilizing bacterial and live algae dosing. It includes natural marine biopolymers that act a bacterial food to help those colonies establish and thrive. Calcium and an array of trace elements, including halogens like iodide, fluoride and bromide are made available to stimulate coralline algae and coral growth. Studies have shown that the insoluble, particulate forms of these minerals and nutrients are much more effective and efficient than soluble liquid forms.

Phos-Start can be added at any time in the 24-hour day, but as many corals open polyps at night, and using the product will temporarily cloud the water, adding it when the light goes out makes the most sense aesthetically and is of the greatest use to the most corals. Once the turbidity subsides, you'll notice that the display water will be particularly clear! Following the instructions and ratios on the container for your referenced aquarium size, mix approximately 200ml of tank water with the prescribed amount of powder and stir vigorously. The starting ratio is 1 small (included) measuring spoon for each 100 gallons of aquarium water. Add this slurry to a high current area of the tank and rinse the cup in the aquarium until no residue remains. Keep in mind that a temporary increase in algae growth is a normal part of the start-up phase in marine aquariums and shouldn't be cause for concern. Temporary browning of some corals may also occur and is a normal part of them reaching the desired nutrient regulation, both of these effects can be mitigated in aquariums that are also being dosed with bacteria and live algae products like those from Nutramar.

For maintaining this environment after cycling the first few months, or for use in biologically stable aquariums, Tropic Marin's Phos-Feed is the product of choice. It is based on all the same natural biological principles that Phos-Start is based on but is formulated for established aquariums. It also offers all the same biopolymers, as well as the insoluble, particulate forms of phosphate, calcium and trace elements that Phos-Start has, just in ratios more conducive to the established marine aquarium.

Application of Phos-Feed is exactly the same as Phos-Start; it can be added to the tank whenever is convenient, but we suggest adding it at lights out for the same reasons. It will also cloud the water for a short period, also resulting in enhanced water clarity once it clears. Mix the Phos-Feed powder with tank water (this is important, don't use reverse osmosis or tap water) and deliver the slurry directly to the highest flow area of the tank. It can also be slowly added to the return chamber of the sump, but make sure this is done in a way to prevent the slurry from settling out in this area, you want it in the main display. The dosage of Phos-Feed is a little different, one small measuring spoon is enough for 50 gallons of aquarium water.

With both these products, you're looking for a phosphate concentration between .05ppm and .15ppm. You can test for this with the Tropic Marin PO4, Professional Phosphate test kit. If you haven't reached these levels within four weeks of starting the dosing, you can increase the dosage slowly. Don't increase either dosage by more than the amount recommended by Tropic Marin. For Phos-Start, you can ramp up to two small measuring spoons for each 100 gallons of water. For Phos-Feed, the ramp up dose is 2 small spoons per each 50 gallons of water.

It's time to stop fearing phosphate, and start looking at it like the nutrient it is vitally important in the correct dosages and the right form to be absorbed by the critters in your tank that need it. If you have too much phosphate, there's solutions for that (and that article exists here on our site too). If you don't have enough, it's important that you take that into consideration as well, and to address it with these revolutionary products from Tropic Marin. Both Phos-Start and Phos-Feed are available from any of our Local Fish Store retail partners. Corals not growing the way you'd like them to? There's lots of different possible culprits but keeping your phosphate levels where you need them is a vital part of this puzzle. Keep testing and Happy Reef Keeping from your friends here at Quality Marine!