Tropic Marin Phos-Start Fast-Acting Phosphate Remover

Tropic Marin Phos-Start is a fast-acting iron hydroxide-based phosphate adsorbent for reef aquariums needing rapid phosphate reduction. Iron hydroxide media binds phosphate (and silicate) with high affinity and pulls it out of solution quickly — useful when phosphate is spiking due to overfeeding, a die-off event, or a neglected system. Run it in a media reactor or a high-flow filter bag in the sump, and replace when saturated — typically every 4–8 weeks depending on phosphate load. It's a tool for managing the symptom; addressing the root cause (overfeeding, dead biomass, inadequate export) is what prevents the need for repeat emergency treatment.