Tank Recommenation - Please

[Vibenz]

My dive buddy is a petite lady in very good shape, so I always end up being the limiting factor when it comes to air. Like most, we are using standard AL80 tanks filled to 3,000 psi.

Now I want to invest in new tanks that will equalize the time we can spend below - and I need some input.

1. The new tanks should not be bigger or heavier than the AL80.
2. The new tank should ideally provide 20% more air than the standard AL80 at 3,000 psi.

A high capacity AL80 filled to 3,300 could of course be an alternative, but not fully meet the +20% citeria.

Steel seems to be the better choice. A 100 cu.ft tank appears to be almost identical to the AL80 when it comes to size, but would that provide the extra capacity I need?

And then the question about LP vs. HP. Some have expressed concerns about the extra strain of HP on the first stage. Is that a real concern?

Steel tanks galvanized, not stainless, I understand. What about rust? What about hot-dip vs. spray/epoxy?

And there is the question about the valve. Any choices there?

Any other issues I should consider? (I am aware of the buoyancy difference.)

Your education effort will be greatly appreciated!

 

[Marie13]

HP80s. Significantly shorter than AL80. Wonderful single diving tanks. I dove them for a few years until I recently went to sidemount exclusively. I’m 5’5”. Shorter people love these tanks.

HP80s are true 80s. Not 77 and change like AL80s.

Get what’s comfortable for HER. Not what you think it should be.

 

[Manatee Diver]

And then the question about LP vs. HP. Some have expressed concerns about the extra strain of HP on the first stage. Is that a real concern?

Unless you are using vintage gear, you really shouldn't worry about that.

 

[runsongas]

hot dip galvanized hp100s unless if you can get overfills consistently in which case lp85s may be better. outside of the discontinued 3500 psi tanks that require a 300 bar din 7/8 unf valve, anything you buy new will be 3/4 NPS and take a modern convertible valve.

 

[scubadada]

To get 20% more gas you need a steel HP100. A little shorter than an AL80. just a bit heavier, better buoyancy characteristics

 

[Lostdiver71]

I agree with the steel HP 100, I have 3 of them and they are my favorite tanks! Plus you can take 6-8 pounds off of your weight belt.

 

[scubadada]

I agree with the steel HP 100, I have 3 of them and they are my favorite tanks! Plus you can take 6-8 pounds off of your weight belt.

More like 4 pounds, but it is good.

 

[Lostdiver71]

More like 4 pounds, but it is good.

You are correct, I am thinking of my Worthington LP tanks which are much heavier. 3-4 pounds less for HP tanks.

 

[shurite7]

There are several options for you.

A. You use the AL80 and she uses an AL63. She will like this option because the 63 is smaller and a little lighter. My former gf loved the 63s.

B. You use a ST100 and she use a ST80. Theses are HP ones (Faber or Worthington, 3442psi). The ST80 is easy to manage.

C. She uses the AL80 (the most common tank with resorts) and you use a HP ST100 or ST120. There is no issue with this option, but no benefit for her in terms of her having a smaller tanks.

D. She can used a ST72 and you use a ST95. These are LP tanks. The option I don’t like about this is, the tanks diameters are different meaning you both have to change your tanks straps when you travel and use other tanks at resorts / operators.

Don’t over complicate this. Rust isn’t a big issue if you don’t run out of air, drain them, or get them filled at a shop that doesn’t maintain the compressor and change the filters.

 

[Vibenz]

Thanks a lot for input - all of you.

I see HP tanks being sold with 200 bar valves. Is that acceptable - or does a 3442 psi / 237 bar tank (eg.Faber HP100-HDG) require a higher rated valve?