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View Full Version : Feelings about NITROX?



spotteddog
08-26-2007, 16:33
What does everyone feel about nitrox?....general feelings, what mix to use, pros and cons?

medic001918
08-26-2007, 16:45
That's such a general question. Nitrox could be a better choice depending on your diving, profile, air consumption, etc. I tend to use nitrox on any deeper dive when I want to extend bottom times. There are people who say it reduces fatigue while diving as well. As far as what mix to use, it all depends on the dive you're planning...as different mixes have a different max depth. If and when you take the course, you'll learn all about how to figure out partial pressure's and max operating depths. Con's are cost, and you have to keep track of your oxygen loading as well as making sure you don't exceed it or you run the risk of oxygen toxicity. All in all, it's not a bad gas. But there isn't a universal answer to your question. The common mixes are 32% and 36%. But it seems like most shops in my area do partial pressure blending and can blend it to any mix I want.

Shane

spotteddog
08-26-2007, 16:49
I was thinking about taking the class before i leave to go to Belize to try to shrink my SI because I will be doing repetative dives for a few days.

thesmoothdome
08-26-2007, 17:22
Definately worth it if you're doing repetative dives on multiple days.

in_cavediver
08-26-2007, 17:25
Nitrox is good. I use it whenever I do long multiday repetetive diving. (well, unless I use trimix or do long dives with o2 deco)

Nitrox does one key thing. It reduces the rate of N2 absorption for a given dive. In a single dive, I doubt it matters, now, do 2 - 3 - 4 dives in a day over several days, you have then significantly reduced the N2 loading. Lower N2, lower decompression stress on you.

Of course, watch your O2 exposure. Its difficult but not impossible for a diver doing rec profiles to get into trouble there.

Kingpatzer
08-26-2007, 17:32
Nitrox = good. There's reason to use regular air, but when the dive profile allows for it, I prefer Nitrox. I honestly believe I feel better after diving when using Nitrox compared to regular air.

porsche060
08-26-2007, 17:46
Just you can't go down to deep,deep depths with nitrox?

Scubacookie
08-26-2007, 17:54
Just finished up the class about a month ago, have not had the opportunity to dive with it, but if it can extend my bottom time, i am all for it. i was a little disapointed in the class, since it has no dive along with it. So I will try it out at a local quarry before i dive into the great big blue.

Capt Hook
08-26-2007, 18:19
I prefer to dive Nitrox, but really only to try and be a little safer at my age.

tnfireman
08-26-2007, 18:22
On multi day/dive trips I like NITROX ,for most of the local diving I'm happy with air.

Zenagirl
08-26-2007, 18:24
I really like nitrox for doing repetitive diving over many days. We dove nitrox for the first week and a half of our back-to-back liveaboard trip this summer, and it was no problem doing 4-5 dives a day. Heck, our computers never even got the nitrogen loading bar out of the green. When the nitrox membrane went down mid-week during the second week, we went back to air and could really see a huge difference in nitrogen loading. Since we hadn't changed anything about our diving it was a really graphic example of the differences for us.

Oh and we didn't notice ANY difference in fatigue levels on or off nitrox.

crosseyed95
08-26-2007, 19:02
I've got mixed feelings about nitrox... Personally when I dive nitrox then I use an air profile. This makes my dive even safer (as long as I do go below allowed depth). However, I don't use nitrox lots and if I do it's when I do multiple dives over several days (that was mentioned in some earlier posts).

I am glad I got certified since it gives me one more option..

SPECIAL NOTE: There are some medical conditions that DAN recommends no Nitrox usage. Those conditions cause these individuals to be more likely to have oxygen toxicity. They can still dive on regular air.

terrillja
08-26-2007, 19:44
My feeling is that Nitrox is so hard to get in rural NH that dedicating tanks to it does not make sense, because for me to get a nitrox fill is around 45 minutes each way, while I can get air at $4 a fill at 30 minutes round trip...

in_cavediver
08-26-2007, 20:08
SPECIAL NOTE: There are some medical conditions that DAN recommends no Nitrox usage. Those conditions cause these individuals to be more likely to have oxygen toxicity. They can still dive on regular air.

OK, this got me. If higher PO2's are an issue, why would any increase be 'OK'. For instance, nitrox 32 at 66feet is a po2 of .96. Air at 130 has a PO2 of 1.05, at 99' its .84. One set is 'OK' and the other is not yet the PO2's are remarkably close.

Personally, I know people have different succeptabilties to oxtox but this 'rule' seems to be a dumbing down. I would teach them all about nitrox and PO2's and what limits they should operate in. Knowledge is power and ignorance here may not be bliss.

in_cavediver
08-26-2007, 20:11
My feeling is that Nitrox is so hard to get in rural NH that dedicating tanks to it does not make sense, because for me to get a nitrox fill is around 45 minutes each way, while I can get air at $4 a fill at 30 minutes round trip...

Depending on the method of making nitrox, dedicated tanks aren't needed. Only PP mixing requires O2 clean tanks which would fit the definition of dedicated tanks. Membrane and premix nitrox require no special cleaning of the tanks.

Now if you use the big bumper stickers - that might be different. I personally use simple contents stickers and mod on all of my tanks. (for air and other gases)

spotteddog
08-26-2007, 20:11
I saw i can take the class online somwhere....its all book work anyway isnt it?....or is it worth the time and money to take it from a real person?

terrillja
08-26-2007, 20:16
My feeling is that Nitrox is so hard to get in rural NH that dedicating tanks to it does not make sense, because for me to get a nitrox fill is around 45 minutes each way, while I can get air at $4 a fill at 30 minutes round trip...

Depending on the method of making nitrox, dedicated tanks aren't needed. Only PP mixing requires O2 clean tanks which would fit the definition of dedicated tanks. Membrane and premix nitrox require no special cleaning of the tanks.

Now if you use the big bumper stickers - that might be different. I personally use simple contents stickers and mod on all of my tanks. (for air and other gases)

All I know is that the 2 shops I have been to in NH that actually do Nitrox fills require tanks marked with Nitrox only stickers. There are other shops, which may not require them, but I know those two do.

in_cavediver
08-26-2007, 20:17
I saw i can take the class online somwhere....its all book work anyway isnt it?....or is it worth the time and money to take it from a real person?

Several agencies have dropped the dives. (at the instructor discretion). The issue of the material - yes it can be done without diving but I wouldn't want to do it online. (seeing/doing the nitrox analysis is important).

That said, another question is would you like two training dives with an instructor to work on other basic dive skills?

dludwig
08-26-2007, 20:27
Love NITROX. I am a pretty big guy (6' 4 & 230#) and have a large lung capacity. I can get much more bottom time on 37% O2. :smiley20:

Zenagirl
08-27-2007, 07:41
I wish I would have been able to take the entire nitrox course on-line and just go to the shop to analyze a tank. However, since there are different types of analyzers the one we "learned" on, wasn't the same brand as on our liveaboard, so the DM had to show us how to use it anyway.

Can't help but think the "go analyze a tank at the LDS" isn't just another ploy to get you to walk in the door of a dive shop.

scubasamurai
08-27-2007, 17:51
ok guys, been to a couple of threads about nitrox, and seems to be mixed, i here alot of people going to depths of 130 ft on nitrox well if you use the 32 or 36 common mixes pa02 are border if not in the toxic range.
i just finished the course just to have to do multi dives a day on a dive boat etc. but what i believe is the truth, that you can't go too deep with the nitrox
opinions, thought, advice for the rookie wannabe DM

in_cavediver
08-27-2007, 21:45
ok guys, been to a couple of threads about nitrox, and seems to be mixed, i here alot of people going to depths of 130 ft on nitrox well if you use the 32 or 36 common mixes pa02 are border if not in the toxic range.
i just finished the course just to have to do multi dives a day on a dive boat etc. but what i believe is the truth, that you can't go too deep with the nitrox
opinions, thought, advice for the rookie wannabe DM

For the record, you most definitely can go too deep on nitrox. I use mostly 32% but then again, where I dive 100' is usually the max hard bottom. Do the math on 36 and see what the PO2 is at 130. (hint 132 is 5 ata so 5x.36=1.8)

Now, many divers have pushed PO2's into that range and many still do. Is it smart? Is it wise considering there are better options (lower PO2)?

I like my max BT PO2 to be 1.3ish over the dive with a deco PO2 of 1.6. No reason to push either envelope because and oxtox at depth wouldn't be fun.

in_cavediver
08-27-2007, 21:48
All I know is that the 2 shops I have been to in NH that actually do Nitrox fills require tanks marked with Nitrox only stickers. There are other shops, which may not require them, but I know those two do.

Yeah, the shops where I go pretty much accept that I go by different rules and don't have the silly bumper sticker rules. (else, do I label then Nitrox, Air, Trimix. What about when I change mixes?)

That said, air is only nitrox 21 so you could still dive whatever you wanted in them with the bumper stickers. The only concern is whether you need O2 clean tanks.

finflippers
08-27-2007, 22:03
I try to dive Nitrox if doing multiple dives. On single dives I usually do air.

scubasamurai
08-28-2007, 11:22
thanks all., i do use it for many dives in one day, its using it for deeper dives that seems it can get you into trouble, but also air can do that and yes your buddy can as well

RECDiver
08-28-2007, 13:56
What do I think about Nitrox? Love it!!!!!!

scubasamurai
08-28-2007, 15:36
that is a good thing

hoop
08-28-2007, 18:56
I just completed the Easy Nitrox Computer class about a month ago.... Going into the class knowing nothing more than "it increases bottom times", I walked away with different thoughts on nitrox.... Not having had a chance to dive with it yet, I can't comment on the physical effects.

However, my original plan of dedicating 2 of my 4 tanks to nitrox had to be re-thought... In Oklahoma, my usual max depth is around 60-70ft, simply because of temperature, and nothing really to see in the black abyss except a muddy bottom (of course, there are some execptions). I feel this would be a waste of dedicating 2 tanks... Air is sufficient for my local diving. Where the nitrox cert. will come in handy is what other people have said; multiple dives on multiple days...(did someone say Bonaire?! :smiley2:)


I was a bit bummed, but I can't justify dedicating several tanks for the kind of local diving I do... But, I can always rent if there is a need!

DirtyWaterIL
08-28-2007, 19:02
My feeling is it's like crack for scuba divers. Once you use it, you will only want more and more until you are out on the street doing God only knows what for more o2 in your tanks.

hoop
08-28-2007, 19:13
My feeling is it's like crack for scuba divers. Once you use it, you will only want more and more until you are out on the street doing God only knows what for more o2 in your tanks.


:smilie39: I love the analogy DirtyWaterIL!!

plot
08-28-2007, 21:48
Do a few deep dives (within the MOD of course.. 100 feet or so), and you'll realize how much more bottom time nitrox gives you over air.

Put your dive computer in plan mode and check what 21% (normal air) vs. 30% would be at a 100 feet.

scubasamurai
08-29-2007, 11:17
will check it out of course as soon as i get a computer hahah. but i do use the nitrox for multi dives to help with the nitro load and it works well