Works its "magenta"!!!Cost very expensive.Product worked great. After one use I could see an improvement in the stains I had in the pool. Some disappeared entirely and others are fading away.This item has some sort of goop or sediment floating in it. I thought that it was just one bottle but the second one has the same issue. The item is not supposed to be like this. The seller should NOT be selling this product. Contacting Amazon.___________UPDATE: Amazon put me in touch with the seller who noted that sometimes there are batch issues. They asked how I would like to remedy the situation, I asked for a refund and received one.EXCELLENT customer service.I use 4 oz every other week in my pool. It seems to keep my water crystal clear and the plastic valve covers white instead of discoloring to yellow as they did before I used this solution. I like it.This stuff took the calcium buildup out of our gunite pool... no acid wash needed. Love this stuffWe just had our pool put in last fall and have used this product every week (when the pool is open), since the install. Once a week, I just walk around the perimeter and sprinkle a total of about 8oz. in the water, which is the correct amount for our pool. It keeps the scale buildup at bay, and my water stays crystal clear. There's some other products out there that say they do the same thing, however my pool intstaller swears by this stuff, and it made me a believer. Highly recommended.This stuff was awesome. I was very skeptical before purchasing. I have a lot of scale built up on my stones of my pool. Within 1 week 90% of the scale was gone where the water level could reach. I have a few spots that the water level is below and it cannot get to, but that is a different issue.This product works!