Phos Stop | High-Capacity Iron-Based Adsorbent (GFO)

Superior Nutrient & Contaminant Control

ATI® Phos Stop is a highly effective, iron-based Granular Ferric Oxide (GFO) designed to provide rapid and reliable removal of phosphates and silicates. Excessive levels of these nutrients are primary drivers of nuisance algae outbreaks and can lead to the degeneration or death of sensitive corals. Beyond nutrient control, Phos Stop also binds organic compounds and heavy metals, such as copper, significantly improving overall water quality and clarity.

Performance & Technical Excellence

Phos Stop is engineered to bind unwanted substances securely, ensuring they are not released back into the aquarium water even as the media reaches its exhaustion point.

• High Binding Capacity: Removes up to 15,000 mg of phosphate and 10,000 mg of silicate per kilogram in marine environments.

• Heavy Metal Removal: Effectively binds up to 8,000 mg of heavy metals (like copper) per kilogram, acting as a safeguard against toxic accumulations.

• Massive Surface Area: With a surface area of 230 m²/g, Phos Stop provides maximum contact time for efficient nutrient adsorption.

• Stability: The iron-based structure is chemically stable and ideal for the high-flow, high-purity requirements of reef systems.

Application & Dosage

To maintain optimal reef health, phosphate should be kept between 0.03–0.1 mg/l (ppm) and silicate below 0.1 mg/l (ppm).

• Standard Dosage: Use 50–150 ml (approx. 30–90 g) per 100 liters (26 gal) of aquarium water. Adjust based on your current nutrient levels.

• Preparation: Rinse the media briefly with RODI water before use to remove any fine dust or abrasion.

• Placement:

  • Media Reactor (Recommended): Use a slow flow rate to maximize contact time. The media should be gently fluidizing or held steady; avoid aggressive tumbling that could cause grinding.

  • Filter Sock: If a reactor is not available, place media in a mesh bag in a high-flow area. Knead the bag occasionally (outside the water) to prevent clumping and channeling.

• Replacement: Monitor your levels regularly. When phosphate or silicate levels stop decreasing or begin to rise, it is time to replace the media.