Confused about lighting

[Dakfish]

I purchased the Hagen Glo 36" double T5HO's, the bulbs are rated at 39wts apiece for a total of 78 watts. They sit on my 46g bowfront. I have been told by two different LFS's 2 different things and am looking for some clarity.
Do T5HO's fit into the "2watts/gal" rule? One estore told me that they are rated the same as any other light set up. But the other store says they are much brighter and can't be held to the "old" rule.

Can anybody help me try to understand if T5HO's are really all that and a bag of chips?

[rocker92]

i would say that they are higher. the are "high output" so thats more light!!!

[bushwhacker]

the t5 lights really are a brighter light the old rule of watts per gallon was based on the t12 light that dont have that intensity

[jpappy789]

There really is no such thing as a "watt per gallon rule"...it's a guideline at best.