The product does work. My only issue is that they don't provide a better scale for administers the product. That is, it would help with the ease of use if they had a chart on the bottle stating how much to add for various sizes. They only provide how much to add to either 25 gallons or 50 gallons. But when I do a 20 water change it can be for as little as 2 qts up to 6 gallons. I have done the math and use a dropper to dispense.
Rating: [4 of 5 Stars!]