Tank Purchase Questions

[halocline]

I was thinking that the tank had to be nitrox enabled, because on scuba.com the tanks they advertise either say nitrox usable up to 40% or nothing about nitrox. Thanks for the heads up.

I'm definitely going to buy used, the aluminum I have is in brand new condition, but I got it off craigslist. The 3442 100 steel is the tank a lot of divers choose?

You can read up on nitrox, O2 cleaning, and tanks. There is ALOT of confusion about it. The basic guideline to keep in mind is that air and nitrox to 40% O2 are basically the same when it comes to equipment protocol. Any gear exposed to higher than 40% O2 needs to be cleaned in a specialized way called O2 cleaning. This includes tanks that will be nitrox filled using the partial pressure method, in which 100% O2 is pumped into a tank along with air at specified pressures to result in the blend you want.

The 3442 PSI HP100s are very popular tanks; they are roughly the size and dry weight of an AL80 yet hold 23% more air. Since you're in north FL, you might have access to shops that will overfill tanks, in which case LP85s and especially LP95s are very popular because when overfilled, they have a very desirable size/capacity ratio. This opens up the can of worms debate about overfilling, though!

None of these topics need be too much of a concern for you at this point in your diving; just enjoy what you have and look for opportunities to try different tanks. For example, my favorite tanks to use, when the dive allows it, are LP72s, which are dirt cheap and hold less gas than an AL80.

 

[DiveMonkeyEZ]

It's a personal choice for any non-pro diver. If you have larger dive op around that has a variety of gear to try out, that may be ideal. I dive mostly warm water, but dive steel now. My main draw was the extra capacity for size. My steel HP120 is about 1" taller than a new AL80, same diameter. And I can fill it to more than the rated 3500psi without worry. My second main draw to her was that the weight difference between full and empty is smaller than the weight difference on an AL80 or AL100. I didn't want the larger diameter, as they tend to not fit tank racks, so this one was perfect. Now I can run down to 300psi and still maintain a safety stop in my 3ml wetsuit with no weights whatsoever. Not having to fool with weights at all is just too cool. If i carry any weight now, it's a 2 or 3lb lead to hand off to a buddy as he's struggling not to float past his safety stop on his al 80

 

[Leadking]

I want to know how you changed the law of physics?

 

[coldwaterdufus]

Mattboy, not 23 % more air in a steel 100 compared to an AL 100, but 23 cubic ft. Compared to an AL 80, this is 23/77 = 29.8% more air .

DiveMonkeyEZ, refering to Leadking's comment, ( which cracked me up even more ) weight of air in a Worthington 120 = 9.68#. The weight of air in a Worthington 100 = 8.3# and the Al 80 = 6.4#. Fairly straight forward, the more air you have ( bigger tanks ) equals the greatest weight difference when you remove the air and the tank is the same.