Buying a single with doubles in mind

[feldomatic]

Folks, I have a problem...

I'm in the middle of researching/planning a drysuit buy and my wife insists I pick up a tank when we go to the shop tomorrow (for the aforementioned drysuit) so I have something wrapped under the tree for the holidays. (I offhandedly mentioned having one would be useful for opening up more night dive opportunities since I can show up late or leave early without having to check a tank in/out from the shop at the quarry, which is my usual m.o.)

Tough life, I know.

That said, I hadn't exactly given a lot of prior thought to what size tank to get.

My first thought is to go with a steel 12L / 80cf, but my question is what size would you recommend if you were going to buy a single today and pair it up with a matching cylinder in about a year to make a set of (back mount) doubles? Is this even recommendable or should I just buy a single with intent to use it as a stage bottle down the line?

 

[runsongas]

HP100 or LP85 (unless if you need short or taller depending on your height) based on how your local dive shop handles fills (eg LP85 if they cavefill or fill everything to 3k, HP100 if they will fill those to 3400+ but the LP85 only to 2640)

 

[Gone for diving]

How long before you want to do doubles?

I would say there are a couple options,
If you are going to dive double all the time after you switch from singles, then get what ever you need for making a double set (don't buy one tank, by 2 singles)

If you want to still dive singles after you have doubles, like for easy dives, then get a 120-130 cu ft,

Or get twin lp50s or lp72s

Unless I am traveling I dive twin 72s all the time.

 

[PEDiver]

I concur with @runsongas above, an HP100 would be the most practical tank since they are great for singles or doubles. If your local dive shop can't (or won't) overfill an LP tank, then I would avoid since it's not the most bang for your buck.

 

[PEDiver]

Or get twin lp50s or lp72s

There is little if any upside to buying LP50 doubles unless you are planning to dive a chest mount CCR. If a shop won't overfill LP tanks, then doubly so. An AL80 or HP100 would be far superior.

 

[Gone for diving]

There is little if any upside to buying LP50 doubles unless you are planning to dive a chest mount CCR. If a shop won't overfill LP tanks, then doubly so. An AL80 or HP100 would be far superior.

I guess it depends on what your doing,
Once you go doubles with redundancy
It hard to go back, to single regulator,
(Unless I am diving double hose reg,)

Sounds like the OP is using aluminum 80s????
So 100cu ft is a massive improvement for dive time and tank weight .

 

[feldomatic]

How long before you want to do doubles?

I'd say 12-24 months.

Sounds like the OP is using aluminum 80s????
So 100cu ft is a massive improvement for dive time and tank weight .

Yep

 

[rob.mwpropane]

In a perfect world you would want 100's with 3/4" npt necks.. but 7/8" unf necks (which are smaller) are fine also, just need to know what you're getting. 3/4" are more desired as they're easier to clean.

Your best bet is getting a set (as already mentioned). You can even get a set with R / L valves already installed that would have a plug for the manifold.

And as if things couldn't get any better, you can save a TON of money buying used tanks. Just make sure they're in hydro or get a guarantee and factor that into the cost and there you go. Somewhere around $4-500, maybe less if you're patient.

I just saved you enough money to take your awesome wife, who has NO idea what she's in for if your heading down this path, out to a nice dinner!

Good luck!

 

[Marie13]

Folks, I have a problem...

I'm in the middle of researching/planning a drysuit buy and my wife insists I pick up a tank when we go to the shop tomorrow (for the aforementioned drysuit) so I have something wrapped under the tree for the holidays. (I offhandedly mentioned having one would be useful for opening up more night dive opportunities since I can show up late or leave early without having to check a tank in/out from the shop at the quarry, which is my usual m.o.)

Tough life, I know.

That said, I hadn't exactly given a lot of prior thought to what size tank to get.

My first thought is to go with a steel 12L / 80cf, but my question is what size would you recommend if you were going to buy a single today and pair it up with a matching cylinder in about a year to make a set of (back mount) doubles? Is this even recommendable or should I just buy a single with intent to use it as a stage bottle down the line?

If you’re diving dry with at least moderate thick undies, steels all the way.

 

[crofrog]

What kind of diving do you want to with the doubles