Premium Granular Ferric Oxide (GFO) - Aquarium Phosphate Remover

Granular Ferric Oxide (GFO) should be used as a part of your tank filtration tools primarily to control phosphate levels. Excess phosphate is one of the main contributors to algae growth, which can quickly become a major problem in a marine system. Controlling your phosphates helps stem current algae issues and prevents future algae outbreaks. This high-performance filter media is made with a premium iron oxide adsorber designed to target and remove contaminants at the molecular level, bringing professional-grade filtration to your aquarium system. With a crystalline α-Ferric oxide hydroxide structure and an exceptionally high surface area, it effectively binds and removes phosphates, helping to prevent unwanted algae blooms and maintain ideal nutrient balance. 🧲 Benefits of Using GFO Removes phosphate (PO₄³⁻) GFO chemically binds with phosphate in the water, effectively removing it from the system and locking it away. Helps control nuisance algae Algae like hair algae, bryopsis, or cyanobacteria thrive on phosphate. Lower phosphate = less algae. Supports coral health High phosphates can inhibit calcification in stony corals (SPS/LPS), making it harder for them to build their skeletons. Keeping phosphate low improves coral growth and coloration. Reduces Tank Maintenance time Reducing phosphates in your tank helps control algae, thereby reducing the time spent cleaning your tank glass. STARTING INSTRUCTIONS Measure out the amount to be used in your tank. The recommended starting amount is around 1 TBSP per every 4 gallons in tank volume. Follow instructions below based on your method: FILTER BAG Add GFO to your filter bag. Rinse the bag with water from your tank or RO/DI water about 30 seconds, or until the water runs clear. Place the bag into your sump or a high flow area of your tank to ensure water is being filtered well through the GFO. Regularly test your tank phosphate levels to ensure GFO is replaced when phosphate levels start rising. MEDIA REACTOR Add the measured GFO to your media reactor. Fill a large bucket with fresh or RO/DI water and place your media reactor’s feed pump in the bucket, and the reactor outlet in a sink. Pump water through the reactor for about 30 seconds, or until the water runs clear. Water entry speed should gently tumble the GFO to avoid pulverizing the media. Carefully dispose of any water remaining inside the reactor before installing. MAINTENANCE INSTRUCTIONS: Phosphate levels may increase rapidly during first time use - monitor with a test kit during the first week used. Replace GFO once phosphates begin to rise after initial use. GFO can be replaced every 4-8 weeks after the initial change, or as needed if phosphate levels begin to increase. Perfect for Use with CaddyStack Both Granular Ferric Oxide (GFO) and Catalytic Activated Carbon work exceptionally well inside our Printed Reef CaddyStack filtration systems. Simply place the media inside an appropriately sized fine mesh filter bag and position it within your CaddyStack chamber to add powerful chemical filtration to your aquarium. Benefits of running media in your CaddyStack include: Easy media changes Improved water flow through filtration media Cleaner sump organization Customizable filtration based on your aquarium's needs Simple maintenance and replacement Important: Filter bags are required when using GFO or Carbon in a CaddyStack and are not included with this product. Be sure to purchase appropriately sized media bags separately before use. Important Shipping Information This product is manufactured and fulfilled by our trusted partner, Perfect Corals. When you place an order through Printed Reef, this item is shipped directly from Perfect Corals and is considered a drop-shipped product. Please note: This product is not manufactured by Printed Reef. Orders containing this item may ship separately from Printed Reef products. If your order contains both Printed Reef products and Perfect Corals products, you may receive multiple shipments with separate tracking numbers. Processing and shipping times for this item may differ from Printed Reef-made products. By offering select products from trusted industry partners, we are able to provide our customers with additional reefing essentials while maintaining the high-quality products and service you expect from Printed Reef.