Pearling stops when my CO2 generator starts to fizz out, too, thus I
think that both CO2 and light are the main factors to get pearling.

Yeah, I would agree. I have over 2 wpg in my moderate-light tank, but it never
pearls. It's not CO2-injected, though. I never had pearling in my high-light
tank (3+ wpg) until I switched to compressed CO2.


Leigh

http://www.fortunecity.com/lavender/halloween/881/