hey just reading along. I am not using co2 at this point and you can see the results. Just lots of air movement.
I am a CG also. I have not done all the steps yet but I am calculating with CMP's help and there is a program to actually save you money for using power on off peak times. You have to enroll in program its not automatic, but can help.
for now your gonna be fine at 50% on your (1)1000w on the seedlings, or just run a t5 for first few sets of leaves. There is no way you need anywhere near that much juice at this point in the grow.