Review on TetraPond Algae Control Block - 1-Ounce, 50-Count by Ebony Smith

I built a backyard pond from scratch. The filter system I made just didn't work. I went to the nearest shop by the pond and bought some of these blocks. The guy told me they work like magic. I put 2 blocks in my 800 gallon pond, one on the deep end and one on the shallow end. Within a few days the water was crystal clear! It was wonderful! So I searched the internet for this product and here it is. This product is highly recommended for this price.