Scuba tanks as oxygen source for wort

Hi

I just picked up three scuba diving tanks. At least one has oxygen in the tank yet.

I would like to use them with a stone to oxygenate my wort pre yeast pitching.

I would think others have done this already and am wondering what I need to be able to connect a tube system up to the tank.

What issues might I be needing to be aware?

Thanks

 

Dont aerate too fast or your wort might get the bends?
-Me

 

Nice

 

A typical SCUBA cylinder holds 3000 psi of air (not oxygen, at least not usually more than 50% and that's very rare) Assuming the cylinder was never allowed to go completely empty and suck in water and the visual and hydro are current, the air in the tank will be well filtered and shouldn't cause problems.

To do this you would need a primary SCUBA regulator to drop the 3000psi down to something that won't destroy everything around it. A primary reg will drop that down to 90-150 psi. From there, you would need a secondary reg (like a CO2 reg, not a secondary SCUBA reg) to drop that pressure down to a workable 0-30psi.

IMHO you would be better off selling one and getting an o2 tank or just an aquarium pump and filter. The compressed air in a SCUBA cylinder is no different than the air you're breathing right now which is basically 21% O2 and 79% N2. So other than having ~ 80cuft of clean dry air in a bottle, you will not be able to oxygenate any faster than an aquarium pump setup.

Having said that, you can get cylinders that have been "oxygen cleaned" and have higher concentrations of O2 in them, but as mentioned above it's almost never more than 50%, more commonly 28% or 32% but it can be whatever the diver specified. This is called Enriched Air Nitrox, EANx or Nitrox and the cylinder will be clearly marked with a big band that it is a EANx cylinder.

Bottom line is unless you have the primary regulator and a spare secondary regulator laying around, coupled with the fact that no reputable SCUBA shop will refill it if you're not certified and getting EANx fills is a separate cert; it's probably not worth it.

Derrin

 

Agreed with above. Sell one tank and buy the O2 kit from Williams with the reg and stone. Use the $30 leftover to buy 4 disposable red O2 tanks.

 

I use a scuba tank with o2. If you have an IP gauge you can adjust the lp pressure down to pretty much whatever you want. You can pick up a gauge at scubatools.com for 30 bucks or so and rig a stone to it. Not the most economical way to go....but I already had about 15 tanks and countless 1st stages.

 

Don't forget that you'll need to get it O2 cleaned in order to get a 100% O2 fill.

 

You could just go all "oxyhacker" on it. Empty the tank, clean it with hot water and simple green. Hang it upside down to dry, or blast it dry with air from another tank. Replace the neck O-ring (does not have to be "O2 compatible"), reinsert the valve and attach a sticker that says it has been O2 cleaned and inspected to "SCUBA Industry Standards" Or, take it to a dive shop and have them do the same for around $50.


Matt

 

Assuming the cylinder is current hydro, you should be able to get ~$75 for an 80cuft AL bottle; $50 if it's out.

On eBay, I bought a 20 cuft O2 bottle and a welding reg for about $120 delivered for both. I had it filled for $8 two years ago and still have well over 1000psi in it. (I'd have to go look). I probably over-oxygenate my wort, I brew 20 gallons about once a month.

I'd definately go this route all over again.

 

Depends on the type of reg...
Some of the piston regs like ScubaPro Mk20's use shims to set the IP. You can only get the IP so low on these regs, like 120ish.
If you have a reg like an Apeks DS4, you can lower the IP much more using the method you described.

 

I use ds4 and diverites. Easy to rebuild/get parts for.