no, the best way that i found which seemed to work is getting barley straw (you can get this free of a farm probably) and just tying it into a large, tight bale and chucking it in the water, leaving it there for a while. You may have been told that straw doesn't work but they probably didn't leave it in long enough. You can also buy this at shops but it's much cheaper if you know a farmer or nip down to a farm. It seemed to reduce mine, so try that. It's a better option than chemicals, as it's always best to avoid adding chemicals. Oh, and UV lights are designed to kill algae, which makes your water green, and blanket weed isn't algae so UV won't really kill it. Hope this Helps!