Oxygen Tank

Does anyone have experience with these home use tanks?
http://images.craigslist.org/01515_24rreH2e0x5_600x450.jpg

It appears to be a deal at $40 + $20-$60 to certify it + cost to fill at the Scuba shop.

Is that a reasonable price? Will it work to oxygenate my wort?

I would check at the Scuba shop first, as most places won't fill the medical oxygen tanks. Because it's medical, it requires a prescription, and most places won't fill it with just the promise that you aren't using it for breathing. Now, if you have an "in" that can get it taken care of, yes, they work perfectly. I use one to oxygenate my wort, and it's nice because it has an actual flow rated valve on it instead of a pressure gauge. That being said, my first one is empty, and the one I'm running now is almost empty, So i'm going to have to try and figure out how to get them filled.

SCUBA shops just fill tanks with compressed air, not pure oxygen. So, even if you could get it filled at a SCUBA shop, you aren't getting the same benefit as pure or highly concentrated oxygen.

You could just get the $10 disposable o2 tanks at HomeDepot. They are already filled and you just throw them out when its empty.

The trick is coming up with the fittings for the Home Depot oxygen tank.


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I purchased the aeration kit from Northern Brewer for $49.99. It included the regulator, hose and diffusion stone. I then purchased a disposable 1.4 oz oxygen tank from my local hardware store for $10.99. The tank provided enough oxygen for seven batches.

The scuba shop said they would fill it, but if its not O2 I am guessing there is no point.

Would an air compressor accomplish the same thing (with a filter of some kind)? I need one of those anyway, the dual purpose makes it easier to justify.

I am also considering an aquarium air pump. Would these alternatives accomplish the same thing as O2, just requiring more time to adequately oxygenate the wort?

No, you will never reach the level of o2 with just an air pump that you would get with pure o2. The air doesn't have enough oxygen in it to reach the same levels. i believe its 8ppm max with an air pump and 15ppms with pure o2.

I only use my o2 system for high gravity beers though.

Here i found this:

The proper amount of oxygen dissolved in wort is 8-10 ppm.

Shaking typically yields around 4 ppm. It's possible to achieve as much as 8 ppm with plenty of headspace and LOTS of vigorous shaking. As an example, 5 minutes of shaking a 1.077 wort may only achieve 2.7 ppm. Siphon sprayers will be in the same range.

Air with an Oxygen Stone can also only reach 8 ppm, regardless of the amount of time the stone is in the wort.

Oxygen with an Oxygen Stone Using a .5-micron stone and a flow rate of 1 L O2 / min, you need around 60 seconds to get 9 ppm, as shown:

30 seconds pure O2 5.12 ppm
60 seconds pure O2 9.20 ppm
120 seconds pure O2 14.08 ppm

The ultimate solution for wort aeration would be one of those oxygen concentrators. There are millions of them out there now, and they can often be picked up reasonably used. They produce well in excess of 90% pure oxygen.


H.W.

Why not just get a welder's oxygen tank? Any gas supplier will refill one of those. Or if you have some reason for not wanting to do that an aviator's oxygen tank.