why does one tank make my mouth so dry, but a different tank doesn't?

[Ladyvalea]

Ok, I went out to Clear springs scuba park and rented a 63 and had just a little problem with dry mouth!

and the next day I dove in a training pool using a LDS tank and my mouth was so dry! I almost wanted to drink the pool water!


Is the quiality the same? like gasoline ?? super, regular supremme?
Cheap air? or maybe its just me?

[rox@ucf11]

although I think it could possibly be quality/bad air I bet it was you were more hydrated the 1st day than the second day, and im sure there are quite a few things other than that, that could account for it

[freeski4ever]

As far as I know, there is absolutely no direct correlation between tank size and humidity of the air within the tank.

[monant]

My guess would be different levels of hydration. Be careful and don't over hydrate. Over hydration is one of the precursors of immersion pulmonary edema. If you're interested, look on the DAN website, they have more information.

[Quero]

I tend to think that it's most likely the compressor filters. Compressed breathing air is supposed to be dry; getting the moisture out of the air by way of filters is standard procedure. Compressed air with a higher moisture content isn't "bad" air for breathing, but it can present certain problems. It's a very, very complex topic, but in an oversimplified way, the problems are:
1) in cold climates, moisture in breathing gas can cause regulator freezing
2) in steel tanks, in particular, moisture in the compressed air can produce corrosion of the metal of the tank, leaving rust particulate suspended in the interior of the cylinder, and these can block tiny air passages.
3) rust particulate may provoke ignition of the oxygen in Nitrox mixes

Here, where the weather is warm, our Nitrox mixes are noticeably drier than our air tanks. So if the tank you got from your LDS contained air pumped in from a compressor that filters agressively for moisture, possibly a compressor also used for Nitrox blends, that could explain the difference you noticed.

[monant]

Moisture in the compressed air is possible. I my previous post I mentioned different levels of hydration because I have my tanks filled from the same compressor and have noticed on some dives my mouth becomes extremely dry and on other dives on different days, my mouth just gets a little dry.

[petronius]

Are you using the same regulator each time? I think some regs tend to be drier than others.

I would guess that your degree of hydration and level of stress also has an impact on dry mouth...

[ScubaDude]

Originally Posted by Quero

I tend to think that it's most likely the compressor filters. Compressed breathing air is supposed to be dry; getting the moisture out of the air by way of filters is standard procedure. Compressed air with a higher moisture content isn't "bad" air for breathing, but it can present certain problems. It's a very, very complex topic, but in an oversimplified way, the problems are:
1) in cold climates, moisture in breathing gas can cause regulator freezing
2) in steel tanks, in particular, moisture in the compressed air can produce corrosion of the metal of the tank, leaving rust particulate suspended in the interior of the cylinder, and these can block tiny air passages.
3) rust particulate may provoke ignition of the oxygen in Nitrox mixes

Here, where the weather is warm, our Nitrox mixes are noticeably drier than our air tanks. So if the tank you got from your LDS contained air pumped in from a compressor that filters agressively for moisture, possibly a compressor also used for Nitrox blends, that could explain the difference you noticed.

I gotta go with Quero on this one.