Tetra Pond 16735 4CT Anti-Algae Block

from Curtis and Kristin

We've been using Tetra Pond Block for several years now in our 250-gal outdoor fish pond after fighting with algae, string-algae and green murky water for years. This stuff works like a charm and ...

from Gregg from Midlo

Have been using this Sludge Reducer for 15 years. Every year the pond is clear and my koi (15) are healthy and have bright colors. Problem what is the largest, powered form I can buy and where bec...

from Happyfountain

This will be my third order of these blocks. I have a 6 foot tall fountain that gurgles up, runs down the sides and is collected in the base to be drawn in and bubbled up again. One of these bloc...

from PondStar

I have used this product off and on for years and always come back to it. Cost was a concern, but in the long run, it's the most economical way to go.

from wheaty

I have a small koi pond and this works great with keeping the algae under control.