Upgradability/future options on a LP steel 121

[EricPuryear]

Hi. I currently have an AL 80, but I've been thinking about getting a LP steel 121. This one in particular:

http://divesales.com/cgi-bin/htmlos.cgi/00213.1.2022230731794544727#st121

I want one for a little extra bottom time, the ability to carry less weight due to the tanks negative bouyancy, and the ability to use this tank in a set of doubles down the road.

My questions are:

1) If I get this tank and decide to do tech diving next year (or otherwise want to use doubles), could I just buy a second tank and the appropriate manifold, Or would I have to buy two tanks and end up wasting money? I *think* that I could just get another tank and a manifold, but I'm not sure...

2) Aside from the buoyancy difference, is there any compelling reason that I should get a HP steel 120 instead?

3) Anything I'm not asking that I should?

Thanks

 

[teknitroxdiver]

1) You think correctly...assuming the second tank is also a 121 (I imagine you knew that, though..)

2) It will be physically smaller, possibly lighter.

3) As long as you can handle the size of an LP121, you'll be fine.

 

[pdoege]

Most of the cave and technical divers around here max out with LP104s / E8 130s.

LP120s are big tanks. By the time you get the dives necessary to go tech your SAC will be good enough that double 120s will just be a pain in the back.

I have had 120s, 104s, 95s, HP80s, AL80s. The tanks that I wish that I had purchased are LP85s/HP100s. I gave the 120s away to a friend in exchange for the 95s....

Peter

 

[tkrock]

I own a OMS LP 121. Heavy as tanks go.

1) shouldn't be a problem doubling. Your thoughts are on the money.

2) LP heavy, HP much lighter.... LP no problem with full fills, HP some places can't hit the 3400 mark.... you note the buoyancy swing....... Controversial remark LP you can over fill and have more air, HP can't (some cave divers do over fills...take the LP from 2400 to 3000 or more)

They are big tanks but not impossible to handle. I love mine!!

 

[jonnythan]

Well... if you decide to go another route, you could just use the LP 121 as a place to keep your car.

LP 120's are GIGANTIC tanks and I recommend not doubling those beasts up.

Those things will be 10 lbs heavier doubled up than my 130s, which are already massively heavy.

Seriously consider some smaller tanks.

http://www.thedecostop.com/forums/showthread.php?t=15344
http://www.thedecostop.com/forums/showthread.php?t=15386

Or the HP100s from here:
http://www.thedecostop.com/forums/showthread.php?t=15442
LP 108's for $185 each, and LP-95s for $175 each..

A lot of people really like the 85s doubled up as well.

 

[abman]

I own a OMS LP 121. Heavy as tanks go.

1) shouldn't be a problem doubling. Your thoughts are on the money.

2) LP heavy, HP much lighter.... LP no problem with full fills, HP some places can't hit the 3400 mark.... you note the buoyancy swing....... Controversial remark LP you can over fill and have more air, HP can't (some cave divers do over fills...take the LP from 2400 to 3000 or more)

They are big tanks but not impossible to handle. I love mine!!

i dive with a l.p. 120 too. i mainly use it on lobster and halibut trips to the channel island trips, due to the fact that truth aquatics only fill to 3000 psi. if i don't use my l.p. 120, i use my double steel 72' with my wing and b.p. diving with either of these set-ups my bottom time is incredible. i don't know if my body could handle packing a pair of steel l.p. 120's. one is a ballbuster by it's self, yet alone 2. i must admit is nice to take the extra weight off my belt, i just re-locate it to my back.lol. ken

 

[EricPuryear]

Thanks for all the help! I'm not too concerned about the weight of the tanks (I'm 6'2" and 220 lbs) but I do care about the size.

According to the charts I've looked at, an AL80 has a diameter of 7.25 inches and a lenght of 26.1 inches, while the LP steel 120 has a diameter of 8.00 inches and a length of 29.2 inches. That doesn't seem too much bigger... Am I missing something, or is an additional 0.75 inches of diameter and 3.1 inches of length a lot?

Also, do you think that the lower pressure of the LP 120 is "better" for my hoses and regulator?

 

[jonnythan]

For singles, 121's will be manageable, but much heavier than necessary.

As doubles they will be practically unusable.

A 121 is 16 pounds heavier than only 3 pounds more negative in the water than an Al80.

By comparison, an LP 95 is about 6 pounds heavier and 4 pounds more negative in the water than an Al80.

A set of doubled up 121's will be on the order of.. 120 lbs.

You might be able to handle one, but two is a totally unnecessary liability, especially when there are more appropriate cylinders for sale for a lower price.

The lower pressure is no better for your regs.

 

[California Diver]

some of my friends have lp 121s, theyre heavy but not that much heavier than my lp108s.

 

[California Diver]

the only advantage to lp tanks is,
1. you can pump then up to hold insane amounts of gas. (lp 120s can hold 400 cu ft)
2. you can get a complete fill off a crappy compressor