My substrate will be flourite and I'm gonna install
undergravel heating cables. I'm hoping to stay away from CO2, but I'll
probably use Flourish Excel on a basis for the carbon and Flourish
for other nutrients.

Don't bother with undergravel heating cables. You'd be much better off putting
that money toward a CO2 system and/or more lighting. Undergravel heating is of
very limited value. Not worth the trouble, IMO.

If I go with three bulbs I
would have 60W or 1.62 wpg. Is that too much for a non CO2 tank?

No. That would be a very low light tank, especially given the almost 2' depth.

With four
bulbs, I'd be at 2.16 wpg, which I'm thinking is definately too much for no
CO2.

I think that would be just right. Around two watts per gallon is good for a
non-injected tank. As long as you stay under 3 wpg, you should be okay. (I
have 2.25 wpg of PCF light over my low-tech tank.)


Leigh

http://www.fortunecity.com/lavender/halloween/881/