i don't know if it's my uv
or something else, but my water is crystal clear (and was on my prior tank as well with it.) i use RO
water now, but just used tap water in Pittsburgh when I lived there. Both tanks were totally clear. I did have some cyano
in my Pittsburgh tank (think the RO
helps with that). I say they can't hurt and likely do well to increase the quality/clarity of the water.