TetraPond Algae Control Pond Block, 4-Count

I was very skeptical about this product. I didn't want to lose any fish and I didn't want to waste money on something that did not work. Our pond algae was out of hand. I placed a block in the waterfall area so it gradually broke down as water flowed out. Just as all the other reviews stated within the first week an incredible difference. One week later, I placed another block again, and the water is nearly clear and I haven't lost any fish.

Have been looking for an effective algae control product for our pond but none worked. Thought to try after reading reviews as we have a lot of sun. We have to use 2 blocks instead of one to better control the algae. Will definitely buy more.

Works far better than the others I have tried. I look no longer. This is the one!

I use these in a 40 gallon tank that has two 6 inch RES turtles in it. It was recommended by the local aquarium shop to keep the algae out of the tank. They work really, really well and resolved our algae problem permanently. My only concern now reading other reviews is that these may be toxic or too strong for a 40 gallon tank? Seems like people are using these in huge ponds. I hope we aren't poisoning our turtles, does anyone know if it is ok to use in a 40 gallon tank, it would be much more concentrated for them.......

Prior to putting 2 pond blocks into our pond, the water was almost pea soup. The pond is about 300+ gallons and after about a week, the water was clear and I could easily see the bottom. Simple to use with great results. 5-STAR