Review on ACCU-CLEAR Water Clarifier for Freshwater Aquariums - Quickly Clears Cloudy Water, Ideal for Weekly Use by Jennifer Lee

We used this product as directed to purify the water in our 55 gallon aquarium. I have used the product before with no problems. but this time (brand new bottle) something was obviously wrong with the chemistry and it killed my entire armored catfish population overnight. Before bed they seemed normal and when we woke up the next morning they were all dead otherwise I would have tried a water change to make a difference. All but one of my Coreys were albinos and some of them lived with us for 10 years. We bred albino measles and our population has expanded by several generations, which is not common but is a healthy environment. My other fish, mostly tetras, were unaffected by the clarifier. On a positive note, the water was actually crystal clear the next day. However, I will never buy or recommend this product again.