I wouldnt classify a 55W PC
to be equivlent to a 110W VHO
. If you put a 55W PC
over a 4' long tank you will get less light over the entire tank than you would with a 110W VHO
. Now if you sample the light over the 2' area of a 55W PC
bulb and compair that with the same light output over the same 2' area of a 110W VHO
then ya I can see how the PC
would be brighter over the same space.
Would 2 55W PC
bulbs be brighter than a single 110W VHO
The watts per gal
rule of thumb does NOT work with MH
I second the recommendation to remove the glass lid. Most of us dont run lids on our salt tanks so we can maximize the air/gas exchange. This will lower your temps a few degrees by it self.
What corals do you want to keep? A pair of 55W PC
's would be fine for most softies. 110W VHO
bulbs are 4' long so they would not work for your setup but a shorter VHO
bulb would. If you did VHO
I would suggest maybe 3 or 4.