On the dime LDS...

[matt_unique]

I dive with double 130s (basically the same as 104s) which are the same diameter as LP120s, though a bit shorter and am able to manage ok. LP120s are indeed an enormous tank, but not completely unweildy. I'm 6' & 150 lbs, so I'm no weight lifter, either .

HP 130's or LP?

 

[Soggy]

HP 130's or LP?

They are PST E8-130s, which fill to 3442psi. They are almost the same as the PST LP 104s (in fact, they are 104 cft at 2640psi). Slightly different buoyancy characteristics.

You're right, though, I wouldn't really want to be walking around with a set of LP120s, but it wouldn't be unmanagable for someone with a large (muscular) build.

 

[matt_unique]

They are PST E8-130s, which fill to 3442psi. They are almost the same as the PST LP 104s (in fact, they are 104 cft at 2640psi). Slightly different buoyancy characteristics.

You're right, though, I wouldn't really want to be walking around with a set of LP120s, but it wouldn't be unmanagable for someone with a large (muscular) build.

You certainly have your back gas requirements covered with those. I use double alum 80's. My rig stand alone (tanks/bands/manifold only) weighs 96 pounds. I would like to have some nice hp steels to mitigate the buoyancy changes with back gas depletion among other advantages. That investment will come later though. My dives are covered with 160cf of back gas for now. You'll have your gas requirements covered for a long time.

--Matt

 

[Soggy]

You certainly have your back gas requirements covered with those.
....

You'll have your gas requirements covered for a long time.

Yeah, there is definitely enough gas in them.

I chose to go with that setup for several reasons....

• I can do literally any dive with these tanks
• Standardization with my buddies (the best reason)
• I already had the tanks as singles
• I hate aluminum tanks on my back
• It cuts down on the number of trips to the dive shop
• I don't really need any additional weight on my belt

The tradeoff is they are kind of heavy, especially since I no longer have any single tanks for shore diving. Once in the water, it's no big deal, though.

 

[Charlie99]

I would like to have some nice hp steels to mitigate the buoyancy changes with back gas depletion among other advantages. --Matt

Does air in an HP steel have a different weight than normal air?

 

[Soggy]

Does air in an HP steel have a different weight than normal air?

No, but steel tanks stay negative vs. aluminum tanks getting wicked buoyant when empty.

 

[matt_unique]

Does air in an HP steel have a different weight than normal air?

A full alum 80 is about 3 pounds negative and will become about 3 pounds positive when emptied. So for doubles this is about a 12 pound shift from full to empty. This is one reason why I would prefer steels. I already had the alum 80's so I decided to use them for now.

--Matt