I have used this carbon product from Polyp Lab for 6 months. The Nitra-Guard Cubes do a good job at eliminating nitrates and phosphates. BIO-Cubes are made from 100% biologically degradable polymers that effectively remove both nitrates and phosphates from both marine and freshwater systems. BIO-Cubes have a very high surface area and contains 400% more carbohydrates than any other brand, making it the best product of it’s kind in the world.

MORE: Nitra-Guard BIO-Cubes Set-up and Review- Polyp Lab