Erm, I didn't measure the dose, but I did put quite a bit in there. Enough to see the water turn milky white. My microsorum wasn't affected by it. But microsorum is a tough plant. I did not dose any of the algae remover directly into my tank.. afraid it might kill my shrimp. I would be careful about dosing this on fragile plants like pellia and crypts though. You've been warned!