Hey everyone, I'm a relatively new diver looking to purchase some equipment in the near future. Although I always dive with a buddy, I would prefer to be as self-reliant as possible, so am thinking a pony bottle would be a good investment. I've tried to research them but have been incredibly confused by conflicting information, so have a ton of questions:
Good questions. I am sure you got some good info, I will tell you what decisions I made, and why.
1.) Does a pony bottle replace the need for a backup second stage from your main tank?
I chose to keep my backgas regulator intact. If you choose to mount your pony on the main tank you may want to use that as the secodnary. To many hoses to contend with get confusing and is harder to streamline.
2.) I see a lot of stuff about pony bottles being attached to a BCD, or turning them on only when needed, and all this stuff. I always thought that a pony bottle was attached to a tank and turned on for the entire dive? Are they just different options, or how do people usually use them?
I chose to sling my pony. A pony is small, and a slight leak can leave you dry when you need the gas. If the pony is slung you can see it leaking and shut it down. Some people prefer to leave it shut down, but I feel this is a bad idea. In an emergency you may forget, take a breath or two, then go OOA again and this time you panic and bolt for the surface. Additionaly I enjoy the option to donate my pony to an OOA diver, and hand him the whole thing, thus reducing my exposure to their potential panic. Also, riding the bottle on my stomach means it is below my center of gravity, or bouyancy while diving. This means it effect my trim far less than if it were on my back, to one side of the tank, pushing me off balance.
Lastly I bungy the second stage to the bottle so it is out of the way and impossible to confuse with anything else, and yes I have a button gauge.
3.) When purchasing, what size would be preferable (assuming the possibility of deep diving in the future - up to 130 feet)? Also, is it generally best to buy a pre-configured system or just buy a tank and regulator yourself? Are they generally easy to switch between tanks (I plan to continue renting my main tanks)?
If deep diving is in your future, a 40 makes sense, as this way you can use it as a stage bottle for deco later in your career. If you intend to stay recreational then I would suggest figuring out how much gas you need to get safely up from the deepest you intend to dive and buy at least that size, if not one bigger to account for anxiety. I purchased a 19cf, it is small enough to disappear, large enough to get me from 100 feet to the surface.
4.) Would you generally fill a pony bottle with air or nitrox? Do pony bottles need a PSI gage to tell how much air is remaining?
This for me is a variable. Right now it is filled with air, however if I am going to be using nitrox on a hard bottom I may choose to fill it with a mix that is within the MOD for the max depth I can achieve. I don't see me ever doing this but it is an option. Anothe option is to fill with a high % mix, but then you lose the deep water bailout option and now you have a "deco" bottle in case you un close to an NDL. In this case I would shut the pony down at depth so I can't pass it off accidentaly. Again I don't see me doing this, but it is an option.
5.) Any recommendations or at least give a rough idea of how much I should be planning to spend?
I spent about about 150 on the bottle, I bought a new setup for my main tank and moved the old one to pony duty. I would say deals could be had for 250 to 350, but this is speculation.
Maybe some of this is new info, but at least if it isn't perhaps the ideas reinforce what other people said and help you make your decisions...good luck