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View Full Version : Pony bottle, 30fc or 40cf?



NightLife
10-14-2007, 15:58
I know there is not a huge difference in size, but I don't want to buy something that is bigger then needed. Do you guys/gals that do deco dives use a 30 or 40cf bottle?

RoadRacer1978
10-14-2007, 16:03
No experience in the matter, just a lot of research on the matter myself. I am planning on getting a pony as well and have contimplated the same question 30cf or 40cf. I think it would mainly depend on what you are planning do with it. A deco dive, just a redundant air supply. How deep are you going to be planning the dive? How much air do you need to reach the surface, how long is the deco stop and how much gas do you need. What is your SAC so you can properly plan on the amount of gas you need.

With my research I am leaning more towards the 40cf. My plans are for now using it as a redundant air supply and eventually as a deco bottle later on when I move in that direction. To me you can't have too much gas when the difference in size is minimal.

skdvr
10-14-2007, 16:18
I just purchased a 40cf and do not do deco but plan on it in the future as well. This is what was recommended to me by a few people on this board. I dove with it for the fist time this weekend and I hardly noticed it was there. It seemed so huge when I pulled it out of the box and thought about it hanging on my d-rings. Really though I hardly noticed it at all. I was even on the bottom most of the time picking up trash and it never really got in my way at all. I know that I will have plenty of redundant air for any dives that I plan in the near future.

If I were you I would just get the 40cf. It can never hurt to have more air than needed.

Phil

ScaredSilly
10-14-2007, 22:42
Std is a 40 cuft. But I have both as I can put pure O2 in the 30cuft.

terrillja
10-14-2007, 23:10
I have a 30CF, it is the same height as my AL80 minus the boot, so it sits on the boot, and the valves are at the same height. It's nice, since it prevents the 30 from sliding down. I personally use the zeagle pony mount, it is cheap (25) and very secure.

texdiveguy
10-14-2007, 23:17
I use a 19cf as a recreational pony bottle, plenty large enough for NDL profiles. My staged deco cylinders range from a 50cf to 80cf and use a steel 72cf for 02 or additional bottom mix as needed.

fire diver
10-15-2007, 09:40
I know there is not a huge difference in size, but I don't want to buy something that is bigger then needed. Do you guys/gals that do deco dives use a 30 or 40cf bottle?

What are your plans for this tank? You say "pony" then talk about "deco."

A pony tank is a small, completely seperate tank filled with (typically) air for use in emergency OOA situations. A deco tank is filled with a specific mix for completing deco obligations faster than with backgas alone.

For a pony, an AL19 or 30 is most common. There really IS a size jump from the 30 to the 40. If you plan on using this for a deco tank, then I would suggest a 40.

FD

NightLife
10-18-2007, 22:02
Plan on using it as a deco tank. I tried a 30cf and it was nice. Now i'll try a 40. I guess for the little difference in size, a 40 wouldn't hurt. Plus I might be able to use it for 2 dives. On the 30 I used about 1400 PSI in about 16 min at a avg depth of 20 feet.

texdiveguy
10-18-2007, 22:32
On the 30 I used about 1400 PSI in about 16 min at a avg depth of 20 feet.

SAC= .54CFM

paintsnow
10-18-2007, 22:55
Plan on using it as a deco tank. I tried a 30cf and it was nice. Now i'll try a 40. I guess for the little difference in size, a 40 wouldn't hurt. Plus I might be able to use it for 2 dives. On the 30 I used about 1400 PSI in about 16 min at a avg depth of 20 feet.

wait, are you actually using the bottle as a deco right now? or are you using it to extend your bottom time

as a pony bottle you shouldn't be using it at all unless its an emergency

texdiveguy
10-18-2007, 23:18
Plan on using it as a deco tank. I tried a 30cf and it was nice. Now i'll try a 40. I guess for the little difference in size, a 40 wouldn't hurt. Plus I might be able to use it for 2 dives. On the 30 I used about 1400 PSI in about 16 min at a avg depth of 20 feet.

wait, are you actually using the bottle as a deco right now? or are you using it to extend your bottom time

as a pony bottle you shouldn't be using it at all unless its an emergency

Sounds to me he is just sample testing bottles and in his statement he did say he was using it as a 'deco' bottle. *But your statement regarding a pony bottle as contingency gas only is 100% correct! Hope he replies back.

danielh03
10-19-2007, 01:42
Trying to pick a pony bottle up as soon as fincances allow.... not to much price difference, but will 10cf really make that much difference if I use it as an RBS?

skdvr
10-19-2007, 05:51
Trying to pick a pony bottle up as soon as fincances allow.... not to much price difference, but will 10cf really make that much difference if I use it as an RBS?

You would certainly think so if you had a 30 and were taking your last bit of air out of it.

Is the bigger tank really that much more of a pain in the but to carry?
I do not think so. I hardley knew my 40 was there when I dove it for the first time.

Phil

fire diver
10-19-2007, 07:38
Trying to pick a pony bottle up as soon as fincances allow.... not to much price difference, but will 10cf really make that much difference if I use it as an RBS?


Whats the one thing you can never have too much of in combat?

whats the one thing you can never have too much of in scuba?

FD

cummings66
10-19-2007, 10:20
Women?

40 cf is more common in that application than 30cf is.

fire diver
10-19-2007, 10:55
Women?

LOL, almost. Judging by Daniels pics, he will know the answer to the first, and set the tone for the answer to the second.

FD

charlesml3
10-19-2007, 12:01
Big question nobody has asked yet:

Do you plan to travel with it?

Traveling with a 40 foot tank is almost impossible. You'll be way over your weight limit for the airline. I only dive warm, clear, tropical water so I rarely go below 100 feet or so. I take a 13 foot pony to use as an emergency bailout only. No deco.

-Charles

fire diver
10-19-2007, 12:05
I have a 40 and a 19. I won't travel with either if I'm flying. Makes no sense to drain, remove the valve, pay for a vis, fill, then drain, remove, re-vis at home and re-fill. THAT is too big of a pain to deal with. I either do with a pony, or I rent a deco cylinder at my destination.

FD

PaDiver93
10-22-2007, 14:22
I have a 30CF, it is the same height as my AL80 minus the boot, so it sits on the boot, and the valves are at the same height. It's nice, since it prevents the 30 from sliding down. I personally use the zeagle pony mount, it is cheap (25) and very secure.


Who is the manufacturer of your 30?

terrillja
10-22-2007, 15:06
I have a 30CF, it is the same height as my AL80 minus the boot, so it sits on the boot, and the valves are at the same height. It's nice, since it prevents the 30 from sliding down. I personally use the zeagle pony mount, it is cheap (25) and very secure.


Who is the manufacturer of your 30?

I believe it is Luxfer, I bought it from ST.

CompuDude
10-22-2007, 17:42
If you're getting into deco diving and plan to use the tank as a deco tank, get the 40. There will be dives you could have gotten away with a 30, but I haven't heard of many serious tech divers who opt for the 30 on a serious deco dive.

If you're planning to use it as a pony, and only occasionally for light deco, you can probably get away with the 30.

Ideally, however, use the right tank for the right application. I suspect as you get more into Deco diving, you'll have a 40, and if you want to dive with a pony, you'll use a 19 or a 30. In other words, you'll end up with both.

So for now, buy the one you will be using NOW. Worry about adding more tanks when you actually need more tanks.