Does nitrox go old in a tank?

[Callo21]

That pretty much sums it up. Thank you for your help.

 

[SteveAD]

No more than air does, and with nitrox you should analyze it before use to confirm, so you'll have proof that it didn't "go old"

 

[Callo21]

well that sucks, because I don't have my own anylizer. I always use the one at the dive shop. It is about 8 months old. Has anyone dived with air or nitrox this old? I was just invited to go up to the lake to dive with some friends and was caught off guard. Thanks.

 

[JeffG]

Don't worry about it, if you have the % marked from the fill. Otherwise you will need to analyze it.

 

[SteveAD]

Cal
you missed the first point of my post that nitrox does not go bad any more than air does. there have been multiple thread on that topic. The continuation related to the fact that many nitrox divers do have their own analyzers and therefore the ability to confirm what common knowledge tells us should be true. I usually analyze my mix when I fill, and again when I pack the truck to go diving, I've never seen a variation of more than 1% between those 2 measurements and this has included time spans of a couple months.

Go Dive Have Fun

 

[bleeb]

Since I see you're a relatively new diver, it's worth a reminder, although you may already have thought of this: If there is excess moisture/humidity inside the tank (from the current or under certain generally infrequent conditions, a previous fill), steel is somewhat more susceptible to using up oxygen (nitrox or air) than aluminum, although it could possibly also happen to aluminum under the right situation. That's one of the reasons for recommendations that nitrox be analyzed 'soon' before use. The global probability of a problem is small, but it's what level of risk you're willing to tolerate.

 

[Callo21]

it is a steel tank. I just don't know if I am willing to risk it?

 

[Callo21]

Cal
you missed the first point of my post that nitrox does not go bad any more than air does. there have been multiple thread on that topic. The continuation related to the fact that many nitrox divers do have their own analyzers and therefore the ability to confirm what common knowledge tells us should be true. I usually analyze my mix when I fill, and again when I pack the truck to go diving, I've never seen a variation of more than 1% between those 2 measurements and this has included time spans of a couple months.

Go Dive Have Fun

I don't know how long air last either?

 

[longk14]

swing by the store and analyze it again

 

[SteveAD]

Since I see you're a relatively new diver, it's worth a reminder, although you may already have thought of this: If there is excess moisture/humidity inside the tank (from the current or under certain generally infrequent conditions, a previous fill), steel is somewhat more susceptible to using up oxygen (nitrox or air) than aluminum, although it could possibly also happen to aluminum under the right situation. That's one of the reasons for recommendations that nitrox be analyzed 'soon' before use. The global probability of a problem is small, but it's what level of risk you're willing to tolerate.

No offense to bleeb, but he's hardly an old salt himself if you have any doubts, simply plan a conservative shallow dive and use air NDLs. But as I mentioned before the immediate pre dive analysis is really just a confirmation that it is what it was.

If you're really nervous bring it in to your shop to re analyze it.Don't blow off a holiday weekend dive over something this minor.

(but if there is some other reason you don't want to dive, don't let someone else push you into it, you don't need any excuse other than I don't feel like it)