Definitely light is more important.

Plants need the following essentials in this order: Light, carbon dioxide,
and trace nutrients.

The trace nutrients are typically made available from uneaten food and fish
waste.

Brian S.

"Spyder2x" wrote in message
news:3gidd.50272$hj.29843@fed1read07...
Hello all,

I am wanting to add both a pressurized CO2 and a nice
lighting system. My question though is which one should I add first? I
currently have a DIY CO2, and around 100 watts of flourescent lights over
a
135 U.S. Gal tank. The lights will be Metal Halide (these are ok for
plants
right?) Thanks for any help.


--Jim--