API POND ALGAEFIX (8 fl oz) Pond Algae Control - Copper Free - Clean, Clear Water - Up to 2400 Gallons - Safe for Fish & Plants - Water Gardens & Fountains - Natural Active Ingredient - EPA-Registered

Works great! This has been the best solution to the algae in my pond and on the rocks in my waterfall without harming my fish! Highly satisfied!

Great product, cleared my pound of an insane amount of hair algae in 3 days. Water lilies and fish show no signs of stress.

I use this in my 75-gallon front yard pond, which has 4 feeder goldfish and solid filtration. At first, I wasn’t sure it would make much of a difference—but after several applications, the water suddenly turned crystal clear. That said, it doesn’t stay that way long. We usually need to reapply once a week, and sometimes even hit it 2–3 days in a row when it clouds up again. In my experience, the dosage instructions are too conservative. The recommended amount didn’t do much, so I doubled the dose (safely) and that’s when I saw results. It’s a bit of a process, but if you stay on top of it, it really works. I’d give it five stars if it lasted longer between applications or worked faster, but overall it’s a solid algae control solution.

It works well it does it says just go by the directions and your algae be gone within a week

It absolutely works. In 3 days, the algae is beginning to be under control and the water looks much more clear. It will likely continue to get more and more clearer in the next few days.

Works, but be very careful!! It will kill your fish!!! I read the instructions and tried to aerate the pond as best as I could. Unfortunately it still killed all of my fish overnight. I can see the bottom of the pond now, but at what cost. Didn’t remove all the algae at the bottom however. There is still a lot that can be stirred up.

Keep pond clear and very easy to use with measuring cap

I've been using this product for years now - I had it on subscription so it sent me a bottle every 6 months. It was all fine until this latest bottle. I put it in a tank and it killed 5 fish. Thinking I may have just mixed up the dosage, when I used it again, I was super careful about dosage. If I didn't notice them acting funny a moment too late and pulled them out and gave them fresh water, another 5 would have died. There was a very strong filter with waterfalls and airs stones, so it wasn't oxygen deprivation. Again, I thought maybe it was just too concentrated for aquariums, so I kept the bottle. I put the baby koi I had in the aquarium out in the pond. There was a lot of algae so I put in the dosage required. It killed one of my adult fish that I've had for years and 3 of my 5 babies. The other two are not out of the woods yet and I've done 2 water changes and its been 3 days and I'm worried about my other adult fish. I was hoping for mating this year, but I doubt they will be able to because they are so close to death. All my mosquito fish except 5 (out of about 1000) have died. Again, this is not about oxygen deprivation, they aren't gasping at the surface. they flash, then die at the bottom of the pond. They won't even float after the death. I don't know what was wrong with the bottle, but don't trust this product. If its bad, it will kill everything and I'm so horrified to loose all my fish. I've been having nightmares and its just awful. DO NOT BUY THIS PRODUCT!! Edit: contacting the manufacturer does nothing either. They won't answer their phone and won't reply if you leave a message. They send a sweet little "call this number" email to every negative review, but apparently won't actually do anything about it. Terrible customer service. I refuse to buy any products by them now. Edit #2: So, I realized that I miscalculated the pond size and thought it was half the volume it actually was. So I was putting in half the recommended dose and it STILL killed my fish

excellent

It works but expensive for ponds

It beats buying the smaller bottles.

Amazing results on just two days. Two months of algae bloom due continuous rain and sunny weather. Never experienced this in with my pond before. Fishes could no longer be seen. Fantastic API Algaefix ... My pond is restored to be crystal clear again.

This product works very well. Fish are very happy and I have a beautiful pond once again.