Just curious about the use of Nitrox in this group of people.
I tend to only use nitrox on no-decompression dives when I am doing deeper dives (100-130) or doing several repetetive dives. On the deeper dives it's to increase my bottom times; for the repetetive dives it's just a safety thing. Other than that, I'll save the cash and use air.
For deco diving, I preffer to use a 50/50 and an 80/20 mix. If I can't use two mixes I'd rather use 50/50 so I can switch at 70 feet.
We have a pump at the club, but no access to Nitrox locally. I am content with compressed air at this point in my dive hobby.
I use air locally in the twin cites area since most of those dives are pretty shallow and I normally don't do more than two dives in a day. For Crosby, Wazee, Superior etc. I like to use Nitrox since I usually do repetitive dives at those sites. I wish Nitrox was more readily available in the twin cities. I think GUDC and SD&T are the only shops now that offer it. I use premix only so my tanks don't need to be O2 cleaned. I like how MN School of Diving does their premix. They have 40% in their banks and will do any mix you want below 40% from that by topping off with air. Locally I think they only have like 32 and 36 percent banked for premix and you have to choose between those two. Not a big deal but it's nice to be able to have the option of selecting a mix from the 40% premix too.
Scuba Center in Eagan also does Nitrox. They are however phasing out the use of premix because TDI is now beginning to frown upon the use of oxygen in a non O2 clean tank.
Wouldn't it be a better idea to make the tanks Oxygen clean? Are they just getting out of having the premix available, or offering EAN completly?
For me I'd say no because otherwise I wouldn't be able to use regular air in them anymore, (well I could but they wouldn't be O2 clean anymore
) and unfortunately I just don't have the cash to shell out on extra tanks to dedicate to nitrox fills only. If premix were not available then I'd unfortunately probably not use nitrox at all.
But, your equipment doesn't need to be Oxygen clean if you are only using EAN40 or less Oxygen. I don't disagree it that it would be nice to dedicate a tank for a particular nitrox mixture, but my understanding is it isn't necessary.
Igotoofar-
What they are talking about is that if premix is not available tanks will be exposed to oxygen and therefore would need to be O2 clean. Once the tanks are cleaned, if you want to use air, it has to be hyperpure and will cost extra $.
To elaborate on what cdtgray said, when they fill your tank with Nitrox if it is not premix they shoot 100% O2 into the tank first and then put air in to get your mix. That is why tanks MUST be O2 cleaned if you are not using 40% or lower premix. You may end up with a 40% or less mix in the end but straight O2 is going in there first to arrive at that mix.