Converting CO2 keg tap to aquarium use - can I do it?

[Guyver]

I've got a 5 lb CO2 bottle and a regulator with a 1/4" inside diameter needle valve and equivalent tubing that runs to a keg tap, and I want to convert the system over to my aquarium. I already have the airline tubing, reactor, and power head necessary to facilitate the set-up, but I have some questions first.

Question #1: Can I even convert the system over? From what I've read and seen, the regulator is the same, minus a much smaller needle valve and a solenoid. Is keg-friendly CO2 the same quality/consistency as aquarium-friendly CO2?

Question #2: I have 1/4" inside diameter CO2 tubing that the regulator has a needle valve for, but I need a new smaller-gauge needle valve and I don't know the dimensions that I would need to facilitate airline tubing. The most narrow-gauge needle valve I've found to date is a 1/4" outside diameter needle valve (1/8" inside diameter), but I'm not sure if this is even small enough. Suggestions and/or websites I can look at for the required needle valve would be VERY handy, since this is all I need to get my system going, provided question 1 is valid.

Question #3: I understand the necessity of a solenoid on the regulator, but is it dreadfully necessary? I'm content to manually turn on and off the bleed valve morning and night (since I'm already feeding morning and night, and when the time comes, fertilizing daily as well), and I'm pretty sure if I leave for the weekend things aren't going to go amuck if I turn off the CO2. Equipping my regulator with a solenoid is something that I haven't researched yet, partly because changing out the bleed valve for a solenoid sounds like a pretty involved and costly endeavor.

Thanks for all the advice to date guys, it really helps!

 

[Purrbox]

The CO2 is exactly the same.

I'm not sure about the needle valve, but you may want to check out Rex Grigg's site as he has a lot of information on putting together your own regulator and may have exactly the answers you're looking for.

A solenoid is not necessary. It's simply a nice to have that allows you to automatically turn the CO2 flow on and off. I run CO2 24/7 on my aquariums without any issues at all. Since I don't have a solenoid, it's one less thing that can fail.