I've used algaefix marine, they don't claim it works on bubble algae but it does, I had a tank with hair algae so I tried it and it worked better on the bubble, no ill effects. Fauna marin algae x does claim to rid bubble but I have not used it.
I find the emeralds just **** it off and it gets worse.
For physical removal I use this, I turn all pumps off and siphon it out as it is scraped off, works great if you can get at it.
