GET IT! GET IT! BEFORE IT GETS YOU!! Small amounts can be controlled. Carefully pull off what you can. What you can't, you can use one of those turkey injectors and inject hydrogen peroxide or a slurry of kalk. While hydrogen peroxide quickly becomes harmless to your tank in small amounts (it quickly turns to hydrogen and oxygen), I would not go crazy. Do it in small batches. You will puncture the bubble, but quickly kill the spores. This is how I controlled it in my 20g nano, and my later 45g. When I transfered everything to my 135g, I missed some. So yes, I am the one who let it get so out of hand that I bought 150# of dry rock to get rid off all my existing rock in my 135g.