So I’m sure alot of people might find this a silly question, but basically I’ve always wanted to be able to breathe underwater. But I don’t live in an area where there is any good place to do any scuba diving, not to mention that scuba gear is way too expensive. I don’t have enough money to buy scuba gear or travel anywhere to do it.

What I’ve been trying to find out for a long time is if there is any way I can actually get a very cheap device to play with. I basically only want to use it as a pool toy, and not much more. I’d never be going deeper than 10 feet tops, and I’d never need more than 10 breaths at a time.

I just found about about the "Spare air" system that looks like exactly what I need although its definely very pricey, and I can’t figure out how much it costs to refill, or if there is any way to perhaps put a schrader valve in the tank, or hook up some other modified tank, so I can refill with a foot pump, or one of those little 12v electric compressors ( I know it will never get up to the true psi, but enough for 5-10 breaths would be good.

For what I’m looking to do (basically just stay under water longer at the pool), is this my best bet, or is there a cheaper option.

One other question on a side note. Before I even found out about this spare air, I actually started building my own device. I used some pressure rated pvc (up to 250psi), to make the tank, and a schrader valve to fill it with my foot pump/electric 12v auto compressor, and it has some air hose leading to a blow valve to blow air in my mouth. Along with a pressure guage and also a regulator I can adjust down to any psi so the air doesn’t blow in my mouth too fast.

Haven’t used it yet since its winter, but it seems like it will work, seems like I’ll get about 5 breaths off the tank if its filled to 120psi, its just so clunky though. Is there any other plans out there for something similar, or a way to cheaply modify my device to have a regular regulator type thing instead of my blowgun valve?

Also, judging by the way my device is made, are there any safety concerns I need to know about? Like I can’t get the bends in 10 feet of water right? And the air from my foot pump or 12v compressor is safe to breathe right? Since neither makes exhaust or takes oil.


A reputable dive shop won’t sell you that Spare Air or Odyssey EAS unless you cough up a C card. They have to look after their own skins. The issue is the fact that you’re attempting to use a compressed gas underwater. That actually requires some training, specifically on how a compressed gas behaves in the human body, how cylinders are filled and storage/handling precautions.
I bet that PVC tank you made has some glued fittings. PVC glue is a carcinogen. You’ll be breathing that in. The air you’re using from that compressor isn’t filtered. A normal compressor used to fill scuba tanks filters the incoming air and the compressor itself is designed such that no hydrocarbons from the piston area are introduced into the tank. I bet that foot pump of yours still uses some form of lubrication. The automobile one has grease in there for sure. Again, you’re breathing the stuff and it’s also a possible fire and explosion risk, but granted, given the tank pressure you’re dealing with, it’s low to the point of non existent but it’s still there and given the right conditions it could happen.
As for the "bends", that’s a depth over time issue.
I’m not comfortable answering the rest of your question regarding improving your device, because if you actually went ahead and used it and anything happened, believe it or not, I could be held partially responsible. So could anyone answering it. Honestly, for the price of that EAS, you could take a course and rent gear anytime you wanted it. You pool bottom time would be in the hour range, not minutes.

Edit: To answer Mike’s further query on this. Yes, he’s missing the second stage. What he has now is the equivalent example of what we’d normally consider an "end the dive NOW" situation. A free flow or a no flow on demand. There’s no demand valve( second stage reg) which is what makes this set up a brief hazardous experience amongst other pitfalls. This "blow valve" of his after ( what I assume to be) his first stage reg, may just be a simple on off valve or no valve at all, hard to tell in the way he’s worded it. That’s as far as I’ll go on the construction of this rig.