Banoo, Water Purifier Cube, Eco-Aquarium Filter Active Carbon ​Ultra ​Strong Filtration and Absorption ​Aquarium Filter ​Media Activated ​Charcoal Cubes ​for Ponds, Fish Tank, Water Tan, 4X4X4 Inch

Bought 2 of the blocks.14 days later, absolutely no change in my 30 gallon fish tank.Do not waste your money!

My fish tank the added filtration is very helpful alone with my other filter

This product doesn't work at all

I love this product and so do my fish. After trying everything to clear the green water in my tank for well over 6 months. I discovered this gem. I put it in my 36 gallon tank and within a week the water was clear for the fist time. I couldn't be happier.

At times my water becomes cloudy due to the shift of the substrate, and or water changes.. I’m not a big fan of dosing my tanks after the fish are in it.. the banoo is a perfect product for the job.. I love it, period.