i have, in my 30. its a 36" length tank with a 30" hood. i was able to fit 3 14w CF 6k daylight bulbs into a perfecto plastic hood casing. lights the tank well and it totals about 42W. significantly brighter than my single 20w T8 that it came with.
for my 5ft long 110 im going with 8 of the same screw in bulbs since 5ft is a weird size, i woulda had to buy a 3ft and a 2ft T8 fixture. buying more than 1 fixture and multiple buls jacks the price up.