TetraPond Pond Block, 50 Count, Helps Control Algae Growth in Ornamental Fish Ponds

My 125 gal. black plastic pond gets algae often during summer and these don’t stop it but greatly reduces the amount of algae. Keep your fish healthy, change water often to reduce ammonia from fish poop and add these as directed.

These are miracle workers, my pond doesn't get as much shade as we would like since we had to plant a new tree due to replacement of pond liner. So we get more algae than most. These work miracles put them in and over night the algae is under control. We purchased every algae thing on the market and used the bales too. Love love love these

Great Stuff! It keeps my pond algae free, my water stays crystal clear and it's safe for fish and plants. I've been using it for years and swear by it. I ordered it from this seller and had it 2 days later, excellent seller! I will buy more things from them in the future for sure.

Works very well on string algae! I have a 800 gallon turtle pond that became overgrown with the algae due to the chlorine in the replenish water. I threw in 10 pods all around and in 2 weeks it was gone. Highly recommend

I've used liquid algae killer and never really knew if I added enough. With these blocks, I threw two in my pond and it started to clear up. Every week I add one to the filter return and it helps. In fact I can't remember when I last was able to see the stones at the bottom. Also, my pond plants didn't suffer and die as some people has posted.

After using various products, I found pond block to use in my pondless water feature. Although not perfect, it did keep much of the algae down throughout the summer. I like being able to use one block a week and forgetting about it. I did find that you need to find the best place for the block. Initially I put it where the water was constantly running over it. This caused the tablet to melt after about a day. Once I moved the block where there was less water flow, it lasted about 7 days. Overall, I am pleased with this product.

Despite being much larger blocks that the 4 packs, these dissolve in HOURS, not weeks as misleadingly advertised and are incredibly ineffective at treating algae, especially string algae. These are also INCREDIBLY toxic, so much so they are illegal to ship to several states. These will kill your fish within months. Garbage product, just buy the liquid versions.

Using these small blocks to keep our fountain cleaner. Works great if we can remember to keep a block or two in there at a time.