RowaPhos — feed your fish and not your algae

RowaPhos (D-D The Aquarium Solution) is the professional method of removing phosphate (PO4) and silicate (SiO2) in all types of aquariums, freshwater and saltwater. It's a unique, patented ferric hydroxide material chemically engineered for the efficient removal of phosphates, silicates and arsenic — initially developed in Germany for treating mains water supplies. Available in 100 ml, 250 ml, 500 ml, 1 L and a 5 kg commercial pack — pick your size on this page.

Why remove phosphate

In the reef aquarium, the manufacturer notes that phosphate feeds nuisance algae and greatly affects coral skeleton formation: it reduces calcification by over 50% and inhibits the deposition of strontium.

What sets RowaPhos apart

Ferric hydroxide based — not to be confused with aluminium-oxide media, nor with iron-based copies from other manufacturers: only Rowa makes RowaPhos
Will not leach what it has adsorbed back into the water
Adsorption capacity printed on the label: 25 g of phosphate per kg
In an independent series of tests by the Berlin Technical University on the five most commonly used phosphate removers, RowaPhos was found the most efficient — the other media tested reached only 30–40% of its removal capacity by weight

Official capacity per size (removal of 3 ppm PO4)

Size	Salt water	Fresh water
100 ml (RP10, media bag included)	400 L (105 US gal)	800 L (210 US gal)
250 ml (RP25, media bag included)	1,000 L (265 US gal)	2,000 L (530 US gal)
500 ml (RP50)	2,000 L (525 US gal)	4,000 L (1,050 US gal)
1 L (RP100)	4,000 L (1,050 US gal)	8,000 L (2,100 US gal)
5 kg (RP500KG, commercial pack)	20,000 L (5,250 US gal)	40,000 L (10,500 US gal)

How to run it

The 100 ml and 250 ml sizes include a media bag, usable in a normal filter. For maximum efficiency, the manufacturer documents fluidising RowaPhos in a reactor — the Aquaforest AF110 media reactor is built exactly for this kind of media. To drive removal by numbers rather than by eye, the Hanna HI774 colorimeter reads phosphate in the ultra-low range.

Frequently asked questions

How much RowaPhos do I need for my tank?

The manufacturer publishes capacity per size for a 3 ppm PO4 removal: for example, the 500 ml treats 2,000 L of salt water or 4,000 L of fresh water. Refer to the official table above based on your volume and starting level.

Is RowaPhos just another GFO?

Not per the manufacturer: it's a patented ferric hydroxide material only Rowa produces — other iron-based media are copies with a different chemical structure, and aluminium-based media are another family altogether.