how long does the air last/go for?
KENNETH E There is no good answer to your question, as time in a tank varies with depth and individual use of air. I bought two of these for my 11 and 14 year old daughters (they are small girls and the 45s work well for them). I recently did a dive with them where they surfaced with about 1000 and I surfaced with 1500 (diving with an 80)...dive was appx 25-30' for 35 min. Hope this helps some...sorry I don't have an "exact" answer.
ROBERT A Everyone will say it depends.....
I say it dosen't matter it's still the best time you could ever have in the underwater world. And it never lasts long enough.
LISA L I actually purchased an aluminum 45. I worked at the Aquarium Restaurant (200,000 gallon saltwater aquarium) and performed a 30 minute dive show one to three times per week. Working at 14 feet, I would use anywhere from 600psi to 750psi per dive, generally staying right around 750psi.
DAVID H IT DEPENDS ON INDIVIUAL BREATHING RATES, CONDITIONS OF WATER AND DEPTH YOU'LL BE DIVING. MY WIFE USES THIS SIZE TANK AND IN CALM, WARM WATER, AT DEPTHS OF NO MORE 25 feet, she get on the average 1 hour bottom time with 500 psi left in tank.
ROBERT K Well, I bought this tank for my daughter - 12 y old, 95lb at that time. For her iti is up to 1h (diving down to 30ft), for me would be probably 30 min. I hope it help. Robert
SCOTT M How long a cylinder will last depends on your depth, and your own breathing rate. If you are a smaller person, diving in warm water, you are very relaxed, diving in less than 50 ft of water, it could last you an hour. If you are a 200 lb. man, who is nervous, diving in cold water, swimming hard against a current at 80+ ft, you might get 20 minutes out of it.
I originally bought one for my Semi-Closed Rebreather as a primary Nitrox supply. It provided over 120 minutes of bottom time in that setup. I've since re-purposed it for my 13-year-old daughter.