View Full Version : Can your air be to dry?

10-08-2007, 13:46
I recently had an air fill from my LDS and the owner had just got his sample reports back. His was -91 degress F. I thought that was great till i dove on that fill! My mouth and throat were so dry after about 5 minutes that i was gagging when I swallowed! Anyone ever delt with this?

WV Diver
10-08-2007, 13:49
If his air check passed it shouldn't be a problem.

On any given day you yourself may notice compressed air being more or less dry depending on if you are well hydrated or not. Have a bottle of water before you dive and see if that makes a difference for you.

ScubaToys Larry
10-08-2007, 14:18
The air has to be very dry due to the physics of compressing it. When you take some air and compress it, it causes the moisture in it to condense. That condensation is trapped in a moisture trap as it leaves the first stage of the compressor. Then it moves to the second stage where again, there is another moisture trap. This continues through all 4 stages of the compression cycle. If it didn't, you'd have an excess of moisture and when it got to the high compression 4th stage - since liquids can't compress, it would blow the rings or head out of the 4th stage.

Every time you hear the compressor cycle off, and every 15 minutes or so or running, you'll hear a big "swoosh" as the drains blow the water out of the system, and empty each of the moisture traps.

Then leaving the 4th stage, the air has to pass through a filter bank where any impurities, and any other moisture gets filtered out.

Steel tanks would rust like crazy if this moisture was allowed to pass through.

So really, all your well maintained compressor and filter systems will give you very, very, very dry air.

It is one of the reasons I use a Bio Filter (http://scubatoys.com/store/detail.asp?PRODUCT_ID=BioFilter) on my reg setup.

10-08-2007, 14:24
my last time i just dived the other day I had a bottle of water before going down and when i came up to do a surface swim with my snorkle in i could barely breath through it due to my throat being so dry, I drink plenty of water before diving too, maybe a bio filter is in the cards for me for my future.

10-08-2007, 18:20
I question whether or not you were hydrated. You can not drink a bottle of water right before a dive and hydrate yourself. To do it properly and have it work you must start days before you dive. If you're hydrated properly you'll find yourself using the bathroom every few hours, that's normal per the doctors. If you go twice a day you're not hydrated, in fact your health would be better if you drink more water.

Urine color is a rough indicator but it won't tell you if you're hydrated right all the time. IE start out dehydrated and drink a bottle of water, gulp it down. You'll hit the bathroom pretty fast and your urine will end up clear real fast, but your tissues haven't absorbed anything. Your fluids can't rebuild to normal levels that fast, all you did was to drink it and pass it back out in almost the same state you took it in.

Proper hydration must by necessity start well in advance of the dive and continue throughout the diving. It takes days to get it right and can not be done right before the dive.

I wonder, when you hydrated how far in advance did you start it? If not at least 3 days out then try that and see how it works for you. Three days out and start drinking water throughout the entire day, aim for your needing to pee every few hours, once you hit that point stay there. Now dive and I'll bet you don't need a bio filter.

10-08-2007, 18:41
Want warm moist air? Check out RB'ers :D

I have no experience with the Biofilter, but I'd like to try it!


10-08-2007, 18:54
I drink a lot when I dive. Usually I will drink two bottles of water before I dive and another one or two between dives and then more after my last dive. This also helps to provide heat for those colder dives.

10-09-2007, 00:01
I have 2 regs. The one I use the most is an Apex (I need sealed 1st stage for most of my diving), and like most reg., the air is very dry. My other reg. is a Mares Proton Metal, and the second stage rocks as far as the air you get, because of it's all metal built it create condensation and thus give you a nice humid air. I wish all second stages were built out of metal.

10-09-2007, 07:23
Get capri-suns
When it gets too bad, crack 'em and drink 'em.

10-09-2007, 09:28
I also struggle with dry mouth when I dive. Think I'm going to have to invest in a Bio Filter in the very near future !!!

Charlotte Smith
10-09-2007, 10:02
Tried the capri sun while under and found it to be the BEST! It was one of the best ideas I have found on the board!

10-09-2007, 15:30
If you have a problem with dry mouth, bring a bag of grapes in your bc. When dry, open the bag and take a grape.

Works like a charm for me.

10-11-2007, 14:45
Bio-filter, Grapes, Capris-suns, Got it now to remember to take this stuff when I go out. I have had dry mouth every time I go out. I just stick my tounge up to the reg when breathing in and it helps me to salivate which gives me a little bit of moisture in my breathes.

10-14-2007, 23:52
Not sure if I could do the capr-sun thing, but grapes I could do! I also have issues with a dry throat & mouth after diving. :smiley11:

10-15-2007, 00:03
i've found that good regs makes for good air.. was using hire regs and found that I was choking underwater and coughing real bad just trying to swallow and wet my mouth.. i thought this was just my getting used to the reg or the air was mixed differently.
i later brought my own oceanic delta 4 reg and went for a dive or 2 and found that I have almost none of the drymouth issues again.. so i put mine down to having a good reg.
LDS also mentioned that when using a reg the air should readily be able to go into the mouth without us having to suck it in really deeply, a small short inhale should automatically trigger the air to jus flow in your mouth.. i found this interesting as i remember sucking away hard on the hire regs and not having to do anything of the sort on my own regs!
hope this helps ..