I just don't have time any more to drive and get the tank filled every week to ten days...
You will need to get a tank, and get it refilled every week or so. It's the 20-lb. tank.
You can get a larger tank, too.
The regulator and photo sensor units are in perfect condition, five years old.
The regulator still goes for $120 new: https://www.titancontrols.net/shop/product/titan-controls-co2-regulator
The photometer turns off the gas flow automatically when the lights are off.
If you want to enhance your grow with carbon dioxide this a very solid and reliable system.
Thank you.