Mini Air Tank for Pool Use

Question
Hi Mike,

Someone else had asked about a small tank to use in their pool.  I've been wondering about the same thing and read your warning about lung expansion.
I have to patch up a small hole at the bottom of my pool which is causing a leak and already have the special underwater concrete filler.

My question is, at the deep end, my pool is only 6ft.  If I were to acquire one of these small air tanks so that I can at least try to spend a few minutes mending this hole, how much at risk am I at traveling back up only 6ft with no training?

Also, are these small air tanks refillable with no training certifications at a scuba shop?  Could they be refilled with any compressor?  I understand these tanks are generally refilled with filtered air, but as you can see, this is certainly not a critical situation.

Thank you!
Mike R

Answer
Hi Mike,

Since you've read my earlier response, then I won't repeat the warnings.  Working in 6 feet of water won't pose the degree of danger as it would if you were working in deeper water but it is not completely hazard free.  Divers know not to hold their breath while using scuba and this would certainly apply to your situation.  This would be your biggest hazard in the pool repair job you are contemplating.

The problem for you would be in acquiring the scuba unit in the first place.  Most dive shops will not provide scuba gear (tanks, breathing regulators or buoyancy compensation vests) to anyone who cannot provide a scuba certification card.  The reason is to prevent untrained people from acquiring this gear and then getting themselves injured or killed by using it incorrectly.  If you bring a scuba tank to a dive shop to be filled, the attendant will want to see your scuba certification card and will also check to make sure the tank has proof of current inspections before filling it.  This, again, is to make sure that untrained people are not exposing themselves to risk of injury by using the tank.

In addition to the tank, you would also need a breathing regulator to reduce the pressure in the tank to a level that you can safely breathe.  Most scuba tanks are filled to about 3000 psi and this is far too great a pressure to use for breathing.  These regulators also fall into the same category as the tanks and should only be used by people trained in their use.

The scuba tanks come in a variety of sizes but the small ones may not be available at your local dive shop.  Most shops carry the ones most commonly used for prolonged diving and are in the 80 cubic foot range.  These tanks are filled to 3000 psi with, as you know, filtered and dried air.  Most home air compressors are incapable of filling to pressures higher than about 200 psi so they are useless for filling scuba tanks.  Additionally, these compressors are not designed to pump air for breathing purposes and pose a real health hazard if used for this purpose.  All compressors are not created equal and that's why the compressors we use for filling scuba tanks are specially made for this purpose and are very expensive.

Mike, I think your best course of action would be to find a friend who is scuba certified and ask him to assist you in patching your pool.  Short of that, ask your local dive shop if they know someone who would be willing to help you.  What you are describing sounds fairly simple and I'm sure there are divers who would be willing to give you a hand.  If you were in my area, I'd certainly help you.

I would not pursue the idea of finding a scuba tank and trying to use it to repair your pool.  There are just too many obstacles to acquiring the equipment and there are risks associated with trying to use it if you're not properly trained in handling high pressure air.

Sincerely,
Mike Giles
Mike's Dive Center