Once Valonia(bubble algaes) become established they can be very difficult to eliminate. I use 4-5 emeralds...a foxface rabbitfish...and manual removal to keep mine in check. The same as all other pest algaes try to remove the source of their nutrients and that will help.I have come to accept that I will probably always have bubble algae in my system...but the combination of predators ...manual removal...and limiting excess nutrients allows me to maintain control over the nasty stuff. I just removed three marble sized bubbles this afternoon...and I'm always looking for them.:thinking: