http://www.polyplab.com/filtration-media-and-resin-waste-management/15-nitra-guard-bio-cubes-v4-80lts-250lts.php 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 [...]
