When I smell ONA I think GROWROOM The only place I ever smelled that stuff. Smell great.
Hang some towels on the inside of your doors for the short term until you can get something that will work.
The air pump should be all you need for DWC, a pump would be used for circulating nutrients between buckets. RDWC
Don't over heat your nutrients 60-70* root rot will ruin your day.
Just make sure you bring in good fresh air to replenish your natural co2.
Get some good advice from some soil guys on a good feeding reg.
Just remember the word "KISS" keep it simple stupid.
You'll do just fine.
Good Growing.
What are you using for a light on the baby?
I started some babies a while ago and they did the same thing, I think it was my light being to close to soon. I pulled it back a little bit and the problem went away.
Re: 1st timer need some advice ;)
A cool tube or a vented reflectors work great for controlling heat issues from your light but if you could use a light without glass you'll have better light quality for your plants.