For me, Vibrant has been great. I had a massive bubble, ulva, and bryopsis outbreak. Since I'm running a 20G nano - I'm limited with what utilitarian fish I can have (for example, a tang would be great but I can't). I did two months of 2mL every other week. It was maintaining, but not killing the bubble algae back. I upped it to 2mL every week, and that seems to be the perfect amount. Once it's all gone, I'll probably go back to every other week and do that forever. I think the trick with Vibrant is to just go super slow - like months before changing the dose. Give it more time to work and if it's not getting any better after a couple of months, then increase.