A few interrelated questions
1. on a 20G high tank, are T5HO lights overkill? Money is not really a constraint, so I was looking at the TEK and catalina fixtures, but I'm not going to spend it if I don't need to.
2. If I ran 4 T5NO 14w 6700k bulbs instead of the HO option, would that be considered moderate or high lighting?
3. If I went to high lighting, do I need to get rid of my low light plants like anubias?
4. is there an amount of lighting where DIY CO2 becomes insufficient?
5. I've read conflicting advice on adding CO2 during lights out/lights on. Which is the best time to add? Also, if using DIY, can you regulate when its on - I assume no.
6. I've read that DIY CO2 smells like a brewery. Is this smell something that will escape the system? How intense/noticeable is it?