lighting question (yes, another!)

[Eric]

I just found a lfs selling a dual 48" t5 "high output" for $159.  This is cheaper than I thought, but would it be cheaper in Ottawa?  And I can't seem to equate lighting from a t5 to wpg or some idea of high medium low lighting.

Can anyone help?  The tank is a 72 g bowfront, I think about 21" high, but I haven't measured lately -- it is getting dusty in my basement during the obsessive planning stage. 

Thanks,

Eric

[BigDaddy]

A T5HO setup would be 54 watts per bulb.  Total of 108 watts.  I have a 75 gallon setup with 2 CF bulbs over it (55W each) and its a good medium light tank.. not great for some "higher" medium light plants.. but the regular stuff grows just fine.

[babblefish1960]

Two t-5 HO bulbs would produce 108 watts, as your tank thinks it is only 21" high give or take some dust, that would be a good source of light for most mainstream medium light plant requirements. Sounds like a good price too.

[Eric]

Thank you both.  A bit embarassed here... For some reason, I thought the wpg calculation didn't apply to T5s.  Planning lighting seems to have lots of math, but I should be able to add up to 108!   
Glad the price is not crazy.  I just may get this tank going yet  
Eric