That's looking really nice Jason! In regards to the co2, I've been reading that the regulators from UP are the least problematic and are pretty good for the money. Personally I would say go for 2x 24 soley because it's almost impossible to find good quality tubes and ballasts in the lower, 14w, tube size. Also with regardes to refilling and buying new, it largely depends, most places charge around £12 in my experience, sometimes you can pick up whole fire extinguishers from ebay for a lot lot less, I've paid a £1 each one in the past! Anubias I believe flower underwater because they don't know they're submerged or something like that, I'll have to re-read K kasselmans book and get back to you.