API POND-ZYME SLUDGE DESTROYER (8 oz) Pond Cleaner with Natural Pond Bacteria - Up to 8,000 Gallons - Reduces Fish Waste Buildup - Consumes Muck & Sludge - Spring Start Up & Regular Care

I use this and the algae fix and between the two I have noticed a huge improvement. This more than the algaecide definitely. I’ve had the pond 10 years and this is the first year the algae is actually slowly coming off the sides and bottom. It’s literally a 7 x 15’ concrete hole in the ground next to the front door with a waterfall and fountain. It’s gorgeous and I put a lot of effort into keeping up with the algae. I have probably 100 fish in there so between uneaten food and waste.. the algae and buildup around the ornaments is just nuts. I mean I could probably get away with less upkeep, but I enjoy interacting with the bigger cichlids and it’s a nice quiet time for me. The ornaments always get caked with algae no matter what. And the rocks and waterfall, too. This doesn’t really help that thick black algae that builds up on the rocks. API makes a waterfall oxi powder but i’m too scared to use it bc i’ve seen reviews saying all their fish died. I may get it and use it on smaller rocks outside of the pond but not in it. Anyway this mainly just keeps the floor and side walls clean. Water too obviously but knock on wood the water has been consistently clean for quite a few years. I’m pretty much just referring to the constant fish waste and algae buildup around the ornaments and in general. I’ve noticed im starting to actually see the cement instead of one thick green blanket up to the water line. The plecos are starting to eat more fish food bc of the significantly lower algae count. Overall i’ve noticed a huge reduction in algae since adding this to my pond maintenance schedule. It’s June now so i’m sprinkling a little bit in every other day and algaefix every 3 days. I’m in Florida and this will probably go on till October when the heat and sun let up a bit. But this is huge volume and the first tub lasted almost a whole year of constant use. Good stuff.

Update- I didn't need to wait a few more days, my pond is now totally clear. Will keep using this along with the algaecide. Last year I found and used an algeacide that worked like a charm for my little backyard pond. It kept it free of algae all summer long, which was a first for me. It is starting to warm up, so I used my tried and true again and my pond kept getting progressively greener. It wasn't working at all. I drained my pond, refilled, then drained and refilled again and hit it hard with the algae control. Still looking terrible. I ordered this and put in the first dose. The first thing I noticed is this floats on the surface for a long time before it sinks and I was worried it wouldn't do much. That night we had a bad wind storm and one of my potted plants ended up in the pond. Great, even more mess. I netted out all the debris I could and figured I'd have to drain and refill this week. This morning I go out, and though all the algae isn't quite gone yet, it is much less so. The water is still a bit murky, but I can see the bottom. With the algae as bad as it was, then the wind storm, I figured it would be a total disaster and it isn't. I think due to this product. I removed and hosed out the filters and one thing I noticed is that the gunk in them is darker brown in color than usual. I think this is the waste and stuff coming out. I gave it a second dose today and hope that within the next few days it is back to normal. It is only going to get hotter, I need to control it now. Anyway, I think this works pretty well, with all the issues it is much clearer than I anticipated it being today. I will continue using and update my review.

I’ve used it in a small outdoor pond and it has helped considerably in removing a large growth of algae.

Does the job. Keeps pond clear

Not goud for ducks

This stuff seams to work well and it hasn't harmed/killed my Koi yet, so that's a plus. I have an 800 gallon Koi pond with six Koi in it. I started using this about a month ago when I brought my pond out of winter hibernation. The water was pretty green last month. I initially went with half the dosing than prescribed because you can never be too cautious with some of this stuff even when they say they're "fish safe". I monitored the behavior of my fish for about a week and started increasing dosing. So far so good. About a month later, my water is crystal clear and my fish seem happy. I will continue to use this product along with a liquid-based natural bacteria product that I use as well.

As always, a little too expensive, but does the job very well. We have a small waterfall pond feature at our front entrance (no fish) but it takes maintenance like any other water pond. This product breaks down solids and somehow lightens the sludge after it breaks the solids. It even destroys leaves over time. Don't bother trying anything else, we have done that for you!

For two and a half years I had no dead fish in my pond. Within days after I added the first dose I had two dead and one stressed fish. Do not buy this poison.

Very happy with this exceptionally easy to use product. Very happy that pond is starting to look better

A little goes a long way. We add it and by the third say the water is crystal clear. We've used it a few time overthe year and it's amazing

Have used this product all the time does seem to help in the Warmer months, to keep the pond water healthy

Very good, did on excellent job on my swimming pool converted to koi pond ( still 5' deep) very happy with this product

Doesn't work. Koi eating it all up, my clear pond water suddenly all murky and covered with brown scum.