Oxygen tank won't put out!

How many batches of beer on average are people getting from those red hardware store 02 bottles. I was a bit shocked yesterday when I was all set to pump some into my wort and nothing came out. I only used it a few times previously. I use about 45-60 seconds worth trying not to foam up the wort. Had to make a mad dash to hardware store before closing time.

Do those valves fit larger O2 tanks? Or do I have to start over with a different setup?

I've used my cylinder for at least 6 batches (2 minutes oxygenation each), and there's still some left. You might have a leak in your system or you're using more than you should. Are your hose connections snug to prevent leaking? Are you using an aeration stone to disperse the gas into the wort or just a plain hose?

-Steve

FWIW, here's my setup:

Oxygen Regulator - For Disposable Tanks w/Barb | MoreBeer

and

Diffusion Stone - .5 Micron (26" long) | MoreBeer

-Steve

I am using this one -
WILLIAM'S OXYGEN AERATION SYSTEM @ Williams Brewing

I suppose I could be using too much. I do remove the valve right after using it.

Are the bubbles that come from the diffusion stone large or small? If they are larger, then perhaps you're using more O2 than I am-- my diffusion stone is 0.5 microns, offers a lot of restriction and makes very tiny bubbles. A larger size diffusion stone would offer less restriction, make bigger bubbles and use more gas. But even that may not make as big of a difference that you are seeing.

Another probability is a leak in your setup-- check the fit of the tubing against the regulator hose barb and the wand.

Maybe you left the gas on and didn't realize it? Or maybe your cylinder had a leak?

-Steve

I had the same experience. Everyone around said I was just using too much O2 but I dunno. I do know those little valves will leak for sure. Anyway, I went ahead and just bought a 20cuft bottle off eBay and a cheap welding reg. i still use the stone and filter from my original deal. I haven't filled the new bottle in 3 years brewing.

The instructions on mine say to remove the regulator when not in use to prevent O2 from leaking.