Like all algae, it grows on excess nutrients, though bubble is known to grow even under very low nutrient level conditions.
Manual removal is pretty much the main option, since few animals will eat it reliably. You can siphon off some during water changes, some are big enough to simply remove, and the tiny ones (new buds) you might be able to get an emerald crab that would feed on them periodically.
I've seen someone use a non-toxic superglue on clumps of them: smear the glue over them, making sure to get it within all the cracks, let it harden up, and then simply remove the cluster whole.
The main thing is to not burst the bubble during removal, which would release more spores into your system, compounding the problem. Some people remove LR into a separate SW-filled bucket during removal in order to reduce this problem.
