This product is the best deal for your money. It is very concentrated and works great. Another name brand product at the same price point needs one gallon for an initial dose (for my size pool!) I only need 16 oz of the Member's Mark product to start and 4 oz a week if I need it for a booster. At first glance, one would think it is expensive, but after you realize you only need 1/8 the product, it is well worth it! It wirks great and keeps my pool free of algea growth.

This product may be a good preventive, definitely does not kill Algae. If you use a pool fountain for cooling, this Algaecide foams even with as little as 4 ounces dispersed at the return. A better product that kills and as a preventive that does not foam is Omni Algae Terminator and using Chlorine Tabs in a floater. Been using this past season when all else failed.

If you're pool never blows air out of the jets, such as you would get if there's a spa connected or solar panels you might not have an issue, but your pool pump does sometime pump some air you will get bubbles. In fact just swimming a lap in the pool will create a trail of bubbles on the water's surface. Additionally, it puts off a chemical smell that tastes nasty when swimming. This all with just 6 ouches added to a 15k gallon pool... Very unhappy. As much as I want to give it 1 star, I'm going with 2 because it might work for some people, and it seems to be effective on the algae. I guess it's back to the 60% stuff for me.

Arrived promptly and received what we ordered. Use this every year in swimming pool.

Have been using this algaecide for 4 years...works great!

I love the way this product keep my pool clean and free of algae.

This works as it should. I did not have foam as the other reviews stated. You won't be disappointed.

It got rid of the green and blue algae which is really all I wanted. I am surprised that I’m still getting a lot of foam when the fountain is running. I believe I diluted it to their specs.

I do not recommend this product. Using this Member's Mark Algaecide 40 created a significant amount of foaming, which had never previously happened with any other product in the 18 years I've had my pool. Even worse was that it was ineffective and I had to purchase a different product elsewhere to re-treat the pool and get rid of the algae.

I just bought and used this. Ignored the pool all winter in NoCal because of all the rains. It was cold and kept the algae at bay but there was a bloom holding steady. Had shocked the pool, swept, cleaned filters (2 huge cartridges for 35k gal pool). Things were clearing but very slowly and with the warmer weather the bloom was ready to explode. I put in about 32 oz. and swept some more. Ran the sweep and pump 24 hrs. Much better. Some foam but not much and nothing that lasted. You could see a clear oil slick on the surface likely due to all the algae lipids and enzymes. I put skimmer socks on both baskets. The sock material would quickly clog up with algae debris. I am washing these out at least twice a day along with the sweep bag. Will add some clarifier in another day (day 3) and clean filters again on Day 5. I expect to have sparkling clear water within a week of addition. Will continue to use as maintenance all year. It is taking care of my algae problem nicely and for a decent price.