Spoiler alert - it was pollen, not mustard algae. We're new pool owners, we bought our house in SC last year from some neglectful owners who let the pool fall into disrepair. For reference our pool is 20 ft x 40 ft, 8 ft at the deep end, 3 feet in the shallow. We spent countless hours and money getting the water clear, and when we finally did, we noticed all of this stuff on the bottom and walls of the pool. Some of it would gather in small circles, some of it would collect in larger masses in the deep end. Some of it was mustard colored, others were dark brown. Everything I read indicated mustard algae. We spent the whole summer in a vicious circle of shocking, vacuuming on waste, filling the water back up, only to have this stuff reappear right as we were done vacuuming. We were using an old suction vacuum with a long hose, which frankly sucked, and not in a good way. It was such a hassle and giant production for no results. The pool was never in a state where we could just jump right in, this stuff was always there. We closed the pool for the winter and had someone come in to open it this spring. The stuff wasn't on the bottom when we uncovered it, but as soon as we turned the filter on, it came on in and settled just as before. We told the pool guy our story. He said it's probably not mustard algae, it's just pollen and fine sediment, and our old vacuum with the giant hose was just stirring up the water. The vacuum wasn't strong enough to suck up the fine debris, it's just moving everything around in the water, which then resettles. The sediment is too fine to be filtered out through the filter. I finally found this vacuum and decided to give it a try. We were AMAZED. It actually picked up ALL of the fine pollen & sediment, did not stir up the water, and since it doesn't have to connect to the filter, you just take all that stuff right out of the pool. It didn't come back after vacuuming. I'm literally in disbelief. The cons: the filter is hard to clean. It's made of fine fibers so bugs and things get caught in there. The charger is annoying. And yes, the vacuum is made of plastic so if you drop it, it will probably break. The vacuum is not for leaves or things much larger than tree nuts (which it does fine with) but we didn't buy it for really big debris. I can't speak to longevity as we've only had it a week, but we bought the 2 year warranty. I figure I have to replace my $1,000 iPhone about every other year, so, ya know, perspective. If I need to replace a $200 vacuum that works this well every 2 years, well, that's a lot less than the amount of money we wasted on shock when we thought we had algae. I hope this helps someone. It turned my very demoralizing situation totally on its head. Pool season here we come!
