Co2 Gone

I built my keezer back in January I got a 20lbs. CO2 tank for it. (Yes, I know this is overkill but for 90 buck and it filled. Why wouldn’t I?) I have had 3 kegs in it so far, and for some reason then tank is now empty. I checked for leaks with soapy water, and found nothing on all of the connections.
The way I have my keezer set up is the CO2 tank inside the keezer with a 3 way distributor. As of right now I only have 2 kegs hooked up, and yes I did make sure the one that was not in use was turned off. I really can not figure out why 20lbs of CO2 would disappear in 4 months. From what I read this stuff should of lasted me for years.
Thanks in advance for your help.

Did you check your kegs for leaks?

I have never replaced my o-rings on the connects on my kegs, nor on the lid (I’ve only lubed them up with mineral oil), and I have a feeling I am losing CO2 somewhere from the keg(s). I only have a 5# tank, but am blowing through them a little quicker than I should be. Sprayed the lines/connections with star san, and didn’t notice any bubbling.

I had CO2 tank issues when I first started kegging. Blew through a few tanks pretty quickly. I believe the problem came from the connection from the regulator to the tank. I picked up some new o-rings and change them with each new TANK (edited). Haven’t had lost a tank since.

Other common CO2 loss areas are from the keg connections. Take them apart, clean them out well, and make sure they are put back together nice and tight.

And then of course there’s the lid. I use keg lube on any keg o-rings for a good seal.

I never found Star-San to find all my leaks so I bought a bottle of this leak detector it will find the smallest of leaks.

http://www.northernbrewer.com/shop/gas- ... ector.html

The o-ring where the regulator connects to the CO2 cylinder is always suspect. The welding supply place where I get my fills gives me a felt washer to put in there instead. Works great because it’s about 1/8 of an inch thick so you can really crank on down on that nut and get it snug and sealed.

Do you have the little Teflon seals where barbs are connected to npt fittings? Check those too. I find windex is better than starsan for me to find leaks.