One Tank for Air and Nitrox

[knotical]

y'all are correct of course. And I'm well aware.
I should have said greater variation - easily managed.

 

[Steve_C]

by up to 1%-5%. It is rare that I am within 1% of what I asked for.

32% is 1.4 at 111 ft
37% is a tad over 1.6 at 111 ft.

I would not accept a fill that is off by 5% nor would I go to a shop that tried to give me that.

 

[Damselfish]

He said deepER, which will give you increased NDL within recreational limits

but well worth pointing out, since it's a common misconception.

 

[eweingarden]

Tortuga - you beat me to the punch line; thanks for pointing it out to Max Bottom Time, although I should have been more clear in my definition. My deeper dives are between 60' and 100'.

It sounds like I should have a dedicated tank for air, and one for Nitrox. I suspect that many shops will either not do an air fill once it has had Nitrox, or, they won't have hyperpure air. I'll admit that I'm not sure on the hyperpure air since I've only rented tanks. I'm now looking to buy, thus my original question.

 

[Tortuga68]

According to your profile, you're not nitrox certified

I suspect that many shops will either not do an air fill once it has had Nitrox, or, they won't have hyperpure air

You suspect incorrectly. And hyperpure air is BS. Do your nitrox course

---------- Post added June 22nd, 2014 at 06:05 AM ----------

but well worth pointing out, since it's a common misconception.

Not really, for an OW diver

---------- Post added June 22nd, 2014 at 06:09 AM ----------

My deeper dives are between 60' and 100'

That's the range where EAN is effective so good idea, but as a newer diver you'll probably run low on air before you hit NDL so better to do more dives first before worrying about nitrox

 

[scoobydrew]

It is possible to get air and nitrox fills in the same tank using methods described above. To see if this will actually work in practice I would contact the places you are most likely going to be getting your fills and see what they say.

 

[boulderjohn]

And hyperpure air is BS. Do your nitrox coursex

I am not sure what you mean by this. Lots of dive shops use special filters for air that will be used in conjunction with oxygen service. Here is one I googled at random--I have no idea about the shop personally.

On the other hand, when I last renewed my PSI inspection certification, I was clearly told Grade E air (used by just about all scuba shops) is good enough.

And if I had a third hand....

The Oxygen Hackers Companion does not advocate this by any means, but it says a skilled filler working with proper care could fill a tank that has not been O2 cleaned safely.

 

[BRT]

The Oxygen Hackers Companion does not advocate this by any means, but it says a skilled filler working with proper care could fill a tank that has not been O2 cleaned safely.

PP filling scares me but I have certainly seen people mixing nitrox that way into non-O2 clean tanks. Because they were my tanks I stood and watched, but I told them that I wouldn't do it with those tanks. They are very skilled and very careful and have not had a problem.

 

[kwinter]

I don't get it. Any shop that blends nitrox will be using clean air, so getting an air fill from the same place is no problem. And most shops in this country will have nitrox and clean air. And even using grade E air should not be an issue. If there is enough hydrocarbon contamination to cause a significant combustion risk on blending the next tank, there would probably have been symptoms of contamination on the prior tank of air.

I also got the impression the OP thought nitrox was for deepER dives rather than shallowER dives. It is a common misconception that should be cleared up in a nitrox course, but often is not.

 

[Dhboner]

The question is actually a little scary...have you had any training with gas mixes richer than 21%. If you think Nitrox is for deeper dives you either have not taken any training or misunderstood what you were taught.