Bubble algae is pesky stuff. As with all algaes, the best approach is to minimize the nutrients that fuel it via sufficient nutrient export (skimming, water changes, refugiums etc). Having said that, once started, it seems to persevere even in well managed systems with low nitrate and phosphate levels. Biologic control can be mildly to very effective. Mitnhrax crabs in my experience has provided very limited contro,l and many aquarists have noted them to occasionally predate on desireable corals. Foxface (depending on the individual fish) can be quite effective. However, sometimes there is no option but to physically remove it from the rockwork. I have done that in one of my displays and it has not (yet) returned. Its a bugger to be sure.