I'm fighting a nice crop of bba and thus far bleach has been the only thing that produces any change in it. However it doesn't seem to have killed it off, just lightened the color of it to a lighter greenish pink and the base of where the bba is growing from is still dark green. I'm using a 1:20 ratio and soaking for three minutes. The plants I've tested in this have no apparent negative effects from the soak after two days. So I would like to try increasing either the length of the soak or the concentration. Any suggestions for how much I could try? Mainly it's java ferns that are having the trouble, but it's also on crypts and hygrophila. I tested a java fern plant and a hygro stem with the bleach but haven't tested crypts since they're harder to remove from the tank.