Need Help? Call us at 1-317-895-9005
or email us at

Proudly serving Aquarists since 1996

Rowaphos 250ML Pack

Item #
Eligible for Free Shipping Program
In Stock

for reliable, effective removal of phosphate from freshwater & saltwater.

ROWAphos is a completely new filter material for eliminating phosphate, which was developed by the Weil Industrieanlagen GmbH company in Osnabrnck, Germany. Due to its unique chemistry, it has the ability to bind large quantities of phosphate by adsorption to its surface without negatively influencing the water in the aquarium in any way.

Why is a phosphate removal system necessary?

Phosphate (PO4) in the aquarium is caused by the decomposition of organic substances. Especially in the confined habitat of an aquarium, several of these decomposition processes are caused from food surplus, dead plant and animal matter, and excretions (animal waste, etc.)

It is very important to maintain PO4 concentrations at very low levels which are in harmony with the aquarium's life and habitat. Natural waters that have not been negatively affected by human use typically show very low PO4 concentrations. However, it is nearly impossible to maintain this ideal condition in an aquarium without an artificial phosphate removal system.

An increase in PO4 concentration leads to unwanted growths of nuisance algae, and to the inhibition of lime synthesis in certain specialized marine organisms in saltwater, such as calcareous algae and stone hard corals.

For more information on Phosphate, click here.

What are ideal phosphate levels for freshwater and saltwater aquariums?

To correct phosphate-induced problems, it is recommended to always keep the concentration of phosphate less than or equal to 0.15 - 0.3 ppm in freshwater aquarium systems (expressed as phosphorus P.)

In saltwater aquarium systems, phosphate levels should always be kept below 0.015 - 0.03 ppm (expressed as phosphorus P.)

How is ROWAphos used to maintain ideal phosphate levels?

The phosphate targets mentioned above can be easily reached with ROWAphos, which effectively binds PO4 without negatively influencing the water in your tank. With ROWAphos, release of potentially toxic substances like aluminum will NOT occur. When exhausted, the product does NOT release phosphate back into the water. ROWAphos should be used regularly, especially in aquaria with very sensitive fish (discus, for example) and in reef aquariums with complex living systems.

ROWAphos can either be used in a canister filter as a separate slow phosphate filter, or, alternately, it can function at the end of the main filter system as the final stage, after the biological and mechanical filters. The material can either be used in the filter net supplied with the pack, or sandwiched between two layers of fine filter wool (on the incoming and outgoing flow.)

Please refer to the table below to determine how much ROWAphos should be used in your system to reduce phosphate in the water column by approximately 3ppm phosphate (measured as PO4-) and to maintain the required low levels on an ongoing basis. The amount of ROWAphos required is determined by both the level of phosphate in the water and the level of phosphate in the rocks, gravel and other substrates within the aquarium.

On new or established aquariums where the phosphate levels are high, first measure the level in the water and assume that 2-4 times that amount may be bound up in the substrate; then adjust the ROWAphos amount accordingly.

Amount of ROWAphos required
to remove phosphate at 3ppm
Aquarium Type
  Description Fresh Water Salt Water
RP10 100 ml packet of ROWAphos 800 liters (200 US gal) 400 liters (100 US gal)
RP25 250 ml packet of ROWAphos 2000 liters (500 US gal) 1000 liters (250 US gal)
RP50 500 ml packet of ROWAphos 4000 liters (1000 US gal) 2000 liters (500 US gal)
RP100 1 liter bucket/tub of ROWAphos 8000 liters (2000 US gal) 4000 liters (1000 US gal)

The lifetime of the filter material, like the usage, depends entirely on the PO4- concentration in the aquarium. Regular control checks with a precise and reliable phosphate test will show the extraordinary effectiveness of ROWAphos. In addition, it can indicate in advance when the filter material needs to be exchanged.

ROWAphos can work for several months in the aquarium before replacement is necessary, depending on the initial phosphate concentration and level of feeding. It is important to remember that with an established aquarium that has not used ROWAphos before, phosphate concentrations may be at exceptionally high levels of 5ppm or more, requiring several treatments over a period of time (as specified above for the tank size) to remove the phosphate from the water column and to eradicate the levels previously absorbed into the substrate and rocks.

For more information, read our tips on how to use ROWAphos or visit the links below.

Customer Reviews

You must be logged in to post a product review.