Weight Question

[Manatee Diver]

OP...Rainbow Reef has AL80’s and AL100’s...not steel 100’s. I’ve never used AL100’s before...we’ll see how that works out for me.

Similar buoyancy swing as an AL80, just a couple of pounds heavier to start, and a couple of pounds more positive at the end. At least for the Luxfer one I dove. The biggest issue are places filling it to 3,000 psi, they have a service pressure of 3,300psi. Also I don't believe you are supposed to use nitrox in them.

 

[rongoodman]

Also I don't believe you are supposed to use nitrox in them.

Interesting, why would you say that? I've used them on several liveaboards with 32%. HP100s are nicer to dive and more compact, but the AL100s are OK.

 

[kelemvor]

Similar buoyancy swing as an AL80, just a couple of pounds heavier to start, and a couple of pounds more positive at the end. At least for the Luxfer one I dove. The biggest issue are places filling it to 3,000 psi, they have a service pressure of 3,300psi. Also I don't believe you are supposed to use nitrox in them.

Nothing wrong with nitrox in an aluminum 100 tank. If you're pp blending the nitrox then the tank needs to be o2 cleaned, but any tank can be o2 cleaned. If it's banked or filled with a membrane, I'm not 100% sure but I think you don't have to get it cleaned.

 

[Barnaby'sDad]

Similar buoyancy swing as an AL80, just a couple of pounds heavier to start, and a couple of pounds more positive at the end. At least for the Luxfer one I dove. The biggest issue are places filling it to 3,000 psi, they have a service pressure of 3,300psi. Also I don't believe you are supposed to use nitrox in them.

The two I have are Catalina and rated to 3,300. They were filled to 3,100 (guessing they lost a bit when they cooled down).

If I realized that I was going to be doing AL100’s instead of steel 100’s...i’d have brought my trim pouches. I can cram a couple more pounds in my bellows pouch if I have to though.

Nice day though. Sunny and 62*. It should get to around 75* today. It’s 33* and raining back home, lol.

 

[Manatee Diver]

Interesting, why would you say that? I've used them on several liveaboards with 32%. HP100s are nicer to dive and more compact, but the AL100s are OK.

Nothing wrong with nitrox in an aluminum 100 tank. If you're pp blending the nitrox then the tank needs to be o2 cleaned, but any tank can be o2 cleaned. If it's banked or filled with a membrane, I'm not 100% sure but I think you don't have to get it cleaned.

I was told it had something to do with the aluminum, oxygen, and pressures above 3,000psi. They are too big for many boat racks so I only dove one a few times, so I am going off of second hand information on the nitrox.

If nitrox is banked or membraned O2 cleaning isn't required, but it is a good idea because banked places can run out. I've seen it happen and one dude that didn't have an O2 clean tank was forced to use air. That is why all my steel tanks, which are primarily used with nitrox, are kept O2 cleaned and checked every vis.

 

[Manatee Diver]

Found a reference to it:
How to Select a SCUBA Tank | Dive Gear Express®

Federal law prohibits the dispensing of pure oxygen at pressures over 3000 psi in DOT-3AL type cylinders, and this would include most aluminum scuba cylinders since nearly all are 3AL class. Recently, the DOT has interpreted this regulation to include oxygen enriched air Nitrox mixtures. If you intend to dive Nitrox, you should avoid selecting high pressure aluminum scuba tanks such as the 3300 psi compact or neutral buoyancy aluminum tanks, or the 3300 psi AL100. Note that this concern does not apply to high pressure steel cylinders, depending on the service pressure of the scuba cylinder it may be filled with Nitrox up to a maximum of 3442 psi.

 

[Nathan Doty]

OP is diving in 80 degree water and comes from Kansas. I only bring this up because I moved to Fl from Wy, where it's omg cold right now. I dive in nothing but a swimsuit and tshirt still, the locals dive in full suits.

So you might not need nearly as much neoprene, so not nearly as much lead needed to offset it.

 

[Barnaby'sDad]

OP is diving in 80 degree water and comes from Kansas. I only bring this up because I moved to Fl from Wy, where it's omg cold right now. I dive in nothing but a swimsuit and tshirt still, the locals dive in full suits.

So you might not need nearly as much neoprene, so not nearly as much lead needed to offset it.

It’s funny that you bring that up. I was diving in a 3mm shorty and was as happy as a fat kid in a cupcake factory. The locals in full 3mm suits were shivering and asking how I wasn’t cold.

 

[Nathan Doty]

I did my class down here obviously. The pool was heated. It was me (I'm 41 at the time) 1 other adult, 1 lady old enough to be my grandmother, and a BUNCH of HS boys. All of the were locals born here. They're in 5mm full suits, everything but a hood and shivering. I'm wearing my swimsuit and felt like I was taking a bath.

In a similar vein, I apparently didn't need to breath. Living at 6-7k feet for a long, looong, toooooo looooooong time gave me very efficient lungs (there's no air up there ). We started at around 3k pounds, doing an air check towards the end of the pool session. All the kids are at 400-700 pounds, we get to me and I'm at 2400. The instructor says "Are you sure you're reading that right? " "Well, if I'm reading the gauge correctly", show it to him. "S***, if anyone needs air during the checkout, FIND NATHAN" :laugh:

I know I've acclimated and I'm new, but I'm also calm in the water so I apparently breathe like a small girl

 

[ScubaSquatch]

OP is diving in 80 degree water and comes from Kansas. I only bring this up because I moved to Fl from Wy, where it's omg cold right now. I dive in nothing but a swimsuit and tshirt still, the locals dive in full suits.

So you might not need nearly as much neoprene, so not nearly as much lead needed to offset it.

I'm planning on the 5mm because it's what I have. I wasn't uncomfortable in the pool with it and the pool was 84 deg. A buddy was down there this same time last year and he said he wished he would have had a 5mm. I'd rather be warm than cold. I can always let some water in to cool off.