HTH67084 Pool Care Algae Guard Advanced, All Algae Eliminator for Swimming Pools - Fast-Acting, Destroys & Prevents Green, Black & Mustard Algae, Keeps Pool Water Crystal Clear, 32 fl oz

Won’t use any other product. I have an older pool & the plaster was looking like it was getting a green tint to it, I have redwood trees around it and I thought maybe I was seeing shadows of the trees making it look like a green tint as well. WRONG this product made the water & plaster so clear. Clearer than I’ve seen it in years, it actually looks blue again!A must buy……

Why did you pick this product vs others?:This truly helped when I had lost hope and really thought there was no coming back for my pool. I plan to use it once a month for maintenance

My experience has been that this product works for 3-4 months minimum per application, which is awesome in my opinion. If it's not working like that, your have other issues with the chemistry in your pool that you need to address first. I also, unfortunately, know this from experience. Get your total alkalinty, calcium hardness, and chlorine stabilizer levels right and this stuff will work for ages. I've had a week here and there where I was lazy about chlorine, and it dropped pretty low but I still didn't get ANY algae, which was an issue before I started using this stuff.This review is specifically for HTH 67289 (the "Ultra", not the "Advanced") which contains copper sulfate, the magic ingredient.

It instantly kills the green alge in the pool, it does however make the pool cloudy.

The mustard algae grew fast after entering the summer time, it's highly pool shock and chlorine resistant, just give this product a shot. It worked! Used it with the clarifier according to the instruction, just needs 4-5 days my beautiful pool came back!

This is the fastest and best algae killer I’ve used and I’ve had my in ground pool for 20 years

Although the price would seem to be high the reality is it is concentrated and you need a lot less as compared to other algaecide products that are typically sold in the gallon size. This is a better buy and works well.

Greatest stuff on planet earth!Clear, Clean Water!It was cloudy all summer, if there’s white algae, couldn’t get rid of it, end of summer found this and dumped 2 bottles into the pool and crystal clear!Bought more and am ready for this summer!