Hey kiddo, let me help straighten out your many problems.
1 Walls- paint them flat white or cover with mylar.
2 Heat- I see signs of heat stress, helping #3 breed even faster, and you're gonna end up with herms in that stressful condition
3 MITES- look under those speckly leaves. I'll bet you find eggs and even webbing.
4 Root rot? Roots are too brown. There is something wrong there.

CO2 is USELESS when your other conditions suck. Don't even consider it until you have fixed the rest of your problems. Those tablets are a ripoff btw... when you are ready for CO2, it's worth doing properly.