Which tanks to choose

[Ross19966]

I have 2 options. We are an hour away from the nearest air fill station so I could 1) Have enough tanks so when I go to get filled I can make it count. Like make a fill trip once a week or 2) buy a compressor and own enough tanks to get through a day and refill after every dive.

That said, I was in the LDS and had my hands on a couple AL80's. They told me I need to go bigger. They said that 80's would give me about 10 minutes on the bottom on a 60 foot dive considering reserve and an ascent safety stop. It's been a while, but I seem to remember 80's not being a real issue when I was diving up in Maine. If I was getting 10 minutes bottom time, I would have done something different.

I thought about HP steel, but it's going to be hard to get them filled to max pressure. LP's wouldn't be a problem filling to rated pressure. For reference, I have dove on AL80's, single and twin and surface air. Some of the company owned twins were probably steel but I can't remember that far back. Price on AL80's in the most attractive, but LP's aren't too bad.

At the moment I'm thinking LP100 - 120. No problem filling to rated pressure at the LDS or at home if I buy a compressor. Steel will also help with weight and trim.

Comments? Thanks.

 

[pauldw]

If your local dive shop can't fill steel hot dip galvanized HP100's, you need to go in there and call them to repentance!

 

[NYCrecdiver]

I got myself two HP 120s. More gas and negative buyoncy.

 

[Ross19966]

Gonna question them again on this. The compressor I'm looking at is the Max-Air 35 gas powered. They say it will go to 4800psi, so I should be able to fill HP's to max rating.

 

[Boarderguy]

HP 100s or larger. AL 80s should be reserved for warm water vacation diving and stage bottles

 

[SlugLife]

1) Have enough tanks so when I go to get filled I can make it count. Like make a fill trip once a week

That's what I've done for now. I keep an eye on the used market, and grab tanks that are 1990 or newer.

2) buy a compressor and own enough tanks to get through a day and refill after every dive.

I'd like to do that at some point. It does require some special knowledge, and isn't as simple as hooking up a "cheap" paintball compressor.

They said that 80's would give me about 10 minutes on the bottom on a 60 foot dive considering reserve and an ascent safety stop.

That sounds silly to me. Maybe at 130ft, you're looking at 10 to 15 minutes of bottom time. I regularly stretch dives in the 45ft to 60ft range close to about an hour overall, and often have air left over.

I thought about HP steel, but it's going to be hard to get them filled to max pressure.

Shops around me have no problem filling steel up to 3500 psi. Though you often have to double-check your fills, because some shops or employees may be lazy.

At the moment I'm thinking LP100 - 120. No problem filling to rated pressure at the LDS or at home if I buy a compressor. Steel will also help with weight and trim.

LPs are fine. HPs are fine too. I'm a fan of my HP 100s, and would like to get some HP120s, if I can find them on the used market. The main factor is really the weight of the tanks. So long as you can handle the weight of bigger or heavier tanks, you might as well go for more air.

 

[Cthippo]

I would find a new dive shop.

I regularly get 30-40 minutes on my steel 72s. Maybe they have some ancient low pressure compressor, but most of the ones I have seen are good to 6000 PSI.

 

[Robert H. Diver]

Get an HP100 or larger as long as they can fill it…which they should be able to…the compressor you are looking at sells for around $3500…that’s not cheap.

 

[boulderjohn]

They said that 80's would give me about 10 minutes on the bottom on a 60 foot dive considering reserve and an ascent safety stop.

That sounds pretty ridiculous.

My math says that if you had a pretty bad air consumption rate and wanted to ensure you and a buddy had enough gas to share air all the way to the surface, including a safety stop, you would still have more than 20 minutes at that depth before beginning an ascent.

What they may be doing is saying you need to have a reserve of 1/3 of your gas PLUS enough for an ascent and safety stop, and that is ridiculously conservative.

 

[TMHeimer]

I traded in my steel 120 because it was heavy to walk with. Also, I find that my AL80s give me plenty of bottom time in Canada. You'll get way more than 10 minutes at 60 feet.