Atomizer sad story: after 2 weeks I decided to clean my atomizer which was still worked fine and put it to bleach for about 30 minutes. That was my fault. After cleaning it was worked well, as I thought, but in fact next day it failed around glue area - there were a hole and all CO2 went through it. No more fine bubbles, just one big bubble. I was unaware of this failure - nobody at shop thought it's abnormal. Very sad. Some plants, like ludwigia super red, are suffered a lot, lost their colors, others are not such much.
Anyway, reverted back to glass diffusor. I'm not sure I'll be trying it again. Very disappointed.
Other not so good news. I'm not happy with area under the tree. It gets too little light for plants to grow properly, had to change my plants to more shade tolerant species, but I'm going to think about changing this layout. Will try to make decent final photo first.