Define good pump / stones. Stones clog and should be changed. A commercial 110l pump is good for no more than six large cylinder air stones (only kind to use). I like to change and add air stones when I move from 5 gal veg sites into 31 gal totes for flower.
CO is incomplete combustion. Co2 is proper combustion.
I've used these http://www.ruralking.com/mr-heater-30-000-btu-propane-blue-flame-vent-free-heater-mhvfb30tblp.html?utm_medium=cpc&utm_source=google&utm_content=060531072&CAWELAID=1624243804&CAGPSPN=pla&gclid=CM2mwrzj4cACFZTm7AodGzwAQw
If one knows what they're doing and builds a smart hydro system, the labor during the actual grow becomes much less, yields increase significantly and the quality does actually improve.
Anyone that fails to understand this has NOT become proficient at hydro and thus has no clue how it good it...
You need to have lots of drainage every watering to rinse out previous feed thus preventing salt buildups in the medium. I see your not equipped to deal with this drainage therefore I feel you will be tempted to under water, building up salts.
Bucket in a bucket grommeted and piped to floor...
Odd that folks find hydro to be such laborious endeavors.
I can forget mine for a week, then about 30 minutes to drain to floor drain and refill.
I spend about three hours a week in that room but it puts out over 15 pounds of top shelf every 75 days.