If I add another 110 watt strip to the tank, that will bring the total watts
up to 220, almost 3 watts per gallon. With that much light will I need to
use CO2 on the tank?


Yes, I would recommend using CO2 with that much light. And with such a large
tank, I'd get a compressed CO2 system.


Leigh

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