Review on Activated Denitrification Filter Media Xport NO3 Cubes by Brightwell Aquatics with Sulphur Doping - Filtration Media for Aquarium Tank by Erica Williams

I've never noticed that my nitrate levels are lower when using these cubes (actually spheres). But my biggest complaint is that after a few months they started breaking down into tiny particles that eventually mixed with the water in my tank. With gentle handling, I removed most of the balls without crushing them, but they became very brittle after only a few months of use. I may have waited too long but I never expected them to start falling apart. The Brightwell Xport PO4 bullets deployed at the same time are still as hard as they were when they started, so only the Xport NO3 bullets crumbled. At the very least, I would put them in a fine mesh bag so that when they fall apart you don't leave a mess on your hands.