Nitrox and Air Tanks

[holstin]

My wife and I have all our own equipment we use when we dive. We each have two tanks with Air in them so we can do two tank dives without refilling. These are brand new and less than 3 months old since we just got certified. We are going to be taking Nitrox classes in the next 6 months after we get more comfortable since we are Newbies. Our LDS is telling us we need to get seperate tanks for Nitrox. Is this truely the case and we will have to purchase third and possibly fourth tanks, or can our existing tanks just be filled with Nitrox and we put stickers on them to track what tank has what. Our Steel tanks were not cheap and I hate to think in the next 6 months we have to purchase more.

 

[Atomic_Diver]

Just get your tanks O2 cleaned.. Much cheaper...

 

[redacted]

It may be the case for your dive shop but it is not the case for all dive shops. Shops that do partial pressure blending usually require O2 cleaned tanks and valves which may also mean dedicated. Most shops that bank nitrox and pump the mix under 40% directly are not conserned with O2 cleaning and should ba able to fill your current tanks. The other question is whether they will require those large nitrox bands or some other more practical marking.

Shop around for a better shop to fill your needs.

 

[TSandM]

There are several ways of blending Nitrox, but a common one involves putting pure oxygen into the tank, and then topping it off with air. The tank and valve must be cleaned well enough for oxygen service, which means removing all oils or greases and replacing o-rings with less flammable ones. This is called getting a tank "O2 clean".

Once the tank has been so serviced, it will remain that way until or unless air is introduced into it that has not been cleaned to Nitrox standards (which is a very, very low level of oils of any kind). If your shop is blending Nitrox, the likelihood is extremely high that the air they are pumping is of Nitrox grade. In that case, you can go back and forth between air and Nitrox at will, so long as you analyze and label the contents of the tank each time you pick it up from the shop.

If the air in your shop isn't O2 clean, then what are they using to blend their Nitrox?

Sounds to me like somebody wants to sell you more tanks . . .

 

[rstofer]

You will learn about the various methods of creating Nitrox when you take your course. If a shop is dispensing banked nitrox (pre-mixed) at 40% O2 or less, the tank doesn't need to be O2 clean. If they do partial-pressure blending (as mentioned by TS&M above) then the tanks do need to be clean.

Once you have them clean, keep them that way by only having them filled with O2 compatible air. This is easy at a shop that does partial pressure blending. By definition, they produce this grade of air for blending.

Now what do you do when you plan a 4 dive weekend? You may not be able to get quality air at the dive site. So, rent some tanks for the extra dives. Sure, they'll probably be Al 80s and you'll need to add weight but it's better than contaminating your tanks. You really don't want to take contaminated tanks back to a shop that uses partial pressure blending. The last time this came up, we rented enough tanks for the entire weekend and left the HP 100s behind.

Unless you run out of NDL before you run out of air, Nitrox isn't for you. Nitrox isn't particularly useful at shallow depths and it has diminishing returns at greater depths. Where is really helps is in the 60-80' range. You'll see this when you take the course.

By all means, take the course. Then decide whether Nitrox has benefits outweighing the 'fiddle' factor. You have to 'fiddle' with your computer, you have to 'fiddle' with gas analysis, you have to 'fiddle' with a log book when you sign for your tanks, and on and on. Even though the computer does all the work, Nitrox is a hassle that might not bring enough benefits.

And then there is the problem of always having the wrong mix in the tanks.

Yes, I have 6 HP 100s full of 36% sitting in the garage waiting for the next outing.

Richard

 

[HowardE]

Our LDS is telling us we need to get seperate tanks for Nitrox. Is this truely the case and we will have to purchase third and possibly fourth tanks, or can our existing tanks just be filled with Nitrox and we put stickers on them to track what tank has what

1) This is not truly the case. You should try to find a different LDS that has more nitrox options than partial pressure fills (in Florida, that shouldn't be so hard). You will learn all about the different filling methods in your nitrox class.

2) Tracking what gas is in your tank is easy, and a simple piece of masking tape will do the trick.

 

[Herk_Man]

I'm going to probably start a fight here but for me (and not everyone) the lack of fatigue I experience after diving Nitrox is well worth any "fiddling" that comes with it. When you add in the increased bottom time, there's no contest. Nitrox is good. Just don't go too deep!

 

[a22shady]

As others have said you can go and just get yout Tanks 02 Cleaned I do not recall how Much but I think it's somewhere around 25-50 again not positive

 

[jmasin]

I'm going to probably start a fight here but for me (and not everyone) the lack of fatigue I experience after diving Nitrox is well worth any "fiddling" that comes with it. When you add in the increased bottom time, there's no contest. Nitrox is good. Just don't go too deep!

NO fighting here. We do it for 2 reasons, margin factor and fatigue.

 

[k ellis]

There are the non believers in nitrox but honestly its the only way to go for anything deeper then 30 feet. There is truth in the fact you are less fatigued after the dives and the extended bottom time alone is well worth it.

I know I probably ruffled some feathers myself but when it comes to nitrox the truth hurts

And yes most any tank can be used for nitrox all you need to do is get it nitrox cleaned. Keep in mind though a nitrox tank is a tank dedicated soley to nitrox. Going back and forth can get very expensive