This is more of a pond/fountain issue but I think the water chemistry should be the same. I have a small pond/waterfall I built in the front yard a few years ago. It’s only 50-80 gallons with a small pump and surrounded by ornamental rocks which also build the rise for the waterfall. I have a constant problem with algae. I’m doing my annual cleaning now and I’m looking for advice. In the past I have tried many algaecide type products with little effect and have used a bit of bleach each week with some success on the algae but it tends to bleach the ornamental rocks a powdery white – kinda defeats the purpose. One guy online said he used a 1 inch chlorine tablet once a week in his small pond and it keeps it clear, but I wonder if I would still have the bleaching problem. The goal is to keep the water clear – no plants, fish, or critters to worry about – and not discolor the rocks. Any advice appreciated. Thx