1-Quart 4-Pack Premium Algaecide 50, Algaecide for Pool, Made in USA

Bought my house a couple years ago, and it had a great pool built about 20 years ago. The coping, as in all older pools, gets pits and crevices and these small areas, mostly on the pool floor, get stubborn black algae. I learned to keep track of my own pool. Though the rest of the pool looks great, there was stubborn black dots around on the floor and on the walls that were just impossible to make go away. My pool is 21k gallons so I poured in the whole bottle of Algeacide 50. I tried to pour around the edges where the greatest concentrations of black algae was on walls and seating areas. Pool was already PH, Alkalinity and Chlorine balanced so after pouring in this treatment I let the filter run. (I have free electricity on the weekends so that's when I initiated this process). You will not notice anything for a day or even two but you will be pleasantly surprised after 5 days to a week. I initially took to the pool with my metal pool brush after pouring in the entire bottle, and would hit it again every other day. My pool is so clean now, and so free of black algae, that I'm almost in shock (pun intended). I have several fountains and spill into the pool from the filter. These created some mild, localized foam for a week or so but it is a small aesthetic price to pay for the amazing effectiveness of this product in completely ridding your pool of all stubborn algea!

Does its job. I recommend it

Great product for the pool

No copper in this algaecide however there is a slight odor post application and a little foaming. The product attacks algae which turns grey and sinks to the bottom of the pool requiring a vacuum. Would advise to clean your filter post vacuuming.

Follow the instructions to much you will be foaming. Does what it is suppose to do my water is crystal clear and would by this product again.

I get these for half the price of what my local pool store wants to charge and it works just as well.

I had heavily shocked my pool to remove mustard algae. This was cleared but as expected spots of black algae remained, I added the full bottle 32 fluid oz of Black Algaecide to my 20,000gal pool per instructions. It is 5 days since the application, and it has had no effect whatsoever on the black spot despite repeated brushing. In my opinion this product was a complete waste of money, and I cannot recommend it

Works great and clears up the algaecide in just hours. Easy to use and makes the pool a nice clean color.