Just most of what they claim the products do is unsubstantiated at best. ie- "Algae Magic" While using this often you will get false high Ammo, nitrite, and nitrate readings according to the instructions. That does not sound good to me. I don't want to use anything that is going to inhibit my ability to know the conditions of my tank. Especially when trying a product for the first time! I guess basically what was already stated-a waste of money and allot of hype.