Phorax binds dissolved phosphate by turning it into water-insoluble aluminium phosphate and holding it in the filter. Capacity is up to 12 mg of phosphate per gram. Reach for it when a test kit shows phosphate above Juwel's targets — 0.05 mg/l in freshwater, 0.01 mg/l in marine.
This is a corrective tool, not a permanent fixture. Aluminium-based binders can pull phosphate down fast enough to stress plants and corals, and at roughly a fortnight per cartridge it is the most expensive medium in the range to run continuously. Test, correct, then stop.
Where it goes
Top of the lower filter insert in a Bioflow M, L or XL. In a Bioflow Super it goes in the upper basket in place of the Nitrax sponge.
Choosing a size
- Medium — Bioflow M: Rio 125 / 180 / 240 LED, Lido 120 / 200 LED, Trigon 190 LED, Vision 180 LED
- Large — Bioflow L: Rio 350 LED, Vision 260 LED
- XLarge — Bioflow XL: Rio 450 LED, Vision 450 LED
Replacement
After approximately two weeks — the shortest interval of any Juwel filter medium.
The rest of the Bioflow range is in our Juwel collection.