75 gallon with plants and fish... How much light?

Grits

How much light is normal to have on a 75 gallon tank? And also, Can you have to much light for the fish to be comfortable?

Right now I have one 48in 40 watt fluorescent light strip. I'm thinking of adding at least another single strip, or maybe even a double. Would that be too much light for my tank?

My Fish:

1 Red Tail Shark
1 Rainbow Shark
1 Zebra Botia
2 Clown Loaches
2 Golden Rams
1 Black Swordtail
2 Common Plecs
3 Cories

My Plants:

A little Elodea and cobomba(not much)
1 fairly large Amazon Sword
1 Hygrophlia
2 smaller plants (I"m not sure of the name)

herefishy

On my 90g, the same footprint as you 75g, only taller, I am using (2)4' T-5 mini HO flourescents with (3) LED moonlights. The 90g is taller than the 75g, and my tank is heavily planted with light lovers. It really all depends upon the density and requirements of the plants. It is a blackwater tank so some of the light is somewhat diminished by the tanins in the water.

Grits

Thanks!

Some people have told me that if I get up to around 2wpg I would need to add co2. I really don't want to get into that yet though.

So, should I be all right as long as I stay under 2 wpg?