First Grow using bubbleponics system

Hello,

I already made a few posts under the stealth hydro system and introduced my problem, received a solution, and joined the Bubbleheads all in one day!...lol...

Anyway, I apparently was having nute lock out with my plants as they are 4 weeks old and still around 4 inches tall with brown and green leaves.

I have now cleaned out the tank using the 8 step recuperation and remedy method given to me here.

I am using the bubbleponics system kit you can purchase at stealthhydro (i'm an affiliate ask for my link..lol) using the dual spectrum lighting with the veg and bloom cfl's that came with the lighting.

These are my current pics after the clean up and change of water ect....will update as needed

I have a question about the air in the tent. I've had people suggest that once the leaves develop we should put some CO2 cartridges in the tent. Is this better for growth? If it's a good idea, where do you find the whippet or release valve for the cartridge...