[reefburnaby]

Hi,

I am assuming the 1.5" diameter tubes right ?

The problem is that 40W and 20W usually uses approximately 430mA of lamp current -- that is the current flowing through the fluorescent tube. In order to overdrive either lamp, you would need to bump up the lamp current -- that is why we attach multiple ballasts in parallel. When we attach the ballasts in parallel, we are driving more current in to the lamp. So the main different between the 40W and 20W tube is the voltage across the tube -- the 40W has double the voltage.

What I am trying to say is that you will need the same amount of equipment to overdrive a 40W as you would a 20W.

- Victor.