CrystalClear Barley Extract Water Garden & Fountain Clarifier, Natural Liquid Concentrate to Treat Cloudy Ponds, Koi Fish, Plant & Pet Safe, 2.5 Gallon

Like the title says, this product is NOT designed to KILL algae. If you want to KILL existing algae you will need a proper algicide. String or mat algae will form when organic materials are allowed to decay in your pond. In my situation we did not get the pond cleaned out in the fall, so once spring hit and the sun came out the algae started to form.We were only using beneficial bacteria and blue pond dye last year, however the combination of these two products prevented mat algae from forming. We now have fish in the pond, so we discontinued use of the blue dye so we could see the fish better. With more sun hitting the pond (which has virtually no shade at the moment), the algae reared its ugly head. Again, since we have fish I did not want to put a chemical in the pond. This is why I chose this product. This product is designed to prohibit the growth of algae, but it will not kill what is already in the pond. If you have algae now you will need to clean/scoop/drain the pond to get rid of what algae is there, then add this product.We have a 16,000ish gallon pond with a natural bog filtration system. We did not drain the pond this spring, rather we used a vacuum to suck out the existing algae and leaves. I then applied 1/2 a gallon of the barley extract along with the proper amount of beneficial bacteria. Using this product GREATLY DECREASED the growth of algae, which is exactly what it is supposed to do. The thing is, you have to use this product WITH your beneficial bacteria EVERY WEEK until you have the issue managed at a level you are happy with.Using a natural product like this helps balance a natural ecosystem by allowing the proper things to thrive in moderation. If this is not something you are willing to tackle, then you might want to consider the chemical route or a UV light system. If your pond is in the open sun like ours, it will be much more difficult for you to control the algae. Plants in and around the pond, shade trees, sun netting, pond dye will all help prevent the bloom of algae, but you will need a combination of things to keep your pond looking decent.

It worked great. The little goldfish pond and the big pond cleared up in less then a week without hurting the animals or plants. Thank you

Very easy to use! Pawn stays nice and clear now :-)

With my High Fin Barbs and al few smails, myu pond is now crystal clear!

Did not clear up pond from algae. Used the whole bottle for less than 50,000 gallons pond and it was supposed to work for up to 70,000 gallons.

I used it as directed by manufacturer. It made no difference in my pond algae.

Added 7.5 gallons of this to our 1/4 ac pond the chart said we only needed 6 gallons, spending over $300 and it did nothing. Did not kill any alge complete waste of money .....

Not sure how much it helped but the pond did clear up eventually.