Bubbles keep getting bigger

[robert serafino]

How big will they get

 

[Jonify]

I haven't seen any bubble coral bigger than that! Nice job!

 

[vetteguy53081]

Typical pearl bubble also called grape bubble. They get quite large and with feedings of plankton can get huge over time.
Its behavior is aggressive and will use its long sweeper tentacles to sting corals that are placed in close proximity to it. It can also sting the reef aquarist who tries to handle it while its sweeper tentacles are out, so precautions should be taken when doing maintenance in the tank. For continued good health, it will also require the addition of calcium, strontium, and other trace elements to the water.
This one looks nice

 

[supernanoguy]

I would imagine they could continue to grown indefinitely.