would al80 be better for me?

[porkchopexpress]

new to diving and picked up a hp100 as recommended for a good overall tank. in just a swimsuit would a aluminum 80 be better? feel like i could dial in my buoyancy in where a hp100 im always going to be heavy and im trying to balance it all on my back. wondering if the hp100 is something you get used to or grab an aluminum?

 

[redacted]

I would think an HP100 (E7) would be about perfect in salt water, but a little too heavy in fresh. You could either just manage the extra 2 to 4 pounds, switch to and AL80, or add a 2 or 3mm shorty.

 

[corvettejoe]

I have AL80's, LP85's, other random stuff, and even an LP108 (heavy as all get out).
I always keep the same weight needs as per an AL80, and just add extra air to my BC for the heavier tanks when I'm in the water. Less to deal with for setup/switching, no need to care about more/less weight. Just add air! This is exactly what a BC is designed to do... provide lift when you're negatively buoyant.

But make sure you know exactly how much weight you need in case you need to use an AL80....and do practice with one or weight yourself out at least so you can figure out what you need should you need to use one. Swap tanks with your buddy sometime during a dive.

 

[Glenn08]

I use a buoyancy tank to trim my twin 50's. The buoyancy of the tank does not change with depth. It means that I wear a little extra lead instead to compensate for my wet suit. Adding air to your BC is an option. If you dive at one depth you will be fine, but if you ascend or descend you will be venting or adding air. You may find the extra air difficult to manage.

 

[2905luvsbubbles]

I would also encourage you to look at your air consumption. If you have "normal" air consumption, you probably are best with an AL 80. Also, using a wet suit should be for thermal protection, not buoyancy. There are a lot of factors that go into tank choice and thermal protection choice. 100's are bigger heavier tanks but give you more air if you utilize more air. If that is the case, going to a 80 will shorten your dive and may put you at the end of the dive before your buddy. A lot of things to consider in the choice of tanks. I use different tanks depending upon the dive I am doing and the thermal protection I am using. I like my steel tanks when I am diving a dry suit, my AL 100 when working with students and my AL 80 when I am diving for my fun.

 

[eelnoraa]

It is all about buoyancy. No need to guess, just do a proper weight check. That means empty or near empty tank, empty BC, you should be able to exhaul and sink. If you can't get properly weighted with HP100 because you are too heavy, your setup is too heavy. Changing HP100 to AL80 is just one way to change your weight. There could be other method. On the other hand, if you still need to add weight to archieve proper weighting, then HP100 isnt too heavy. When allow, I think HP100 is a better tank than AL80.


I also respectfully disagree about using the same weight between different tank and just add air to BC. It is dangerous practive. In OP's example, HP100 is -2lb empty, AL80 is +4lb empty. That means you need 6lb more while diving AL80. Now, keeping the same wieght and switch to HP100 meanings you are 6lb over weighted with a empty tank. Add 8lb of air of HP100, you are 14lb negative at the beginning of the dive. Even not considering wetsuit compression, if BC fail, you will sink to the bottom like a rock.

 

[Croomrider]

You should be ok in salt water with the HP-100. It is physically smaller than an AL-80 but is about the same weight empty out of the water. Most people need to add weight to get properly weighted for an AL-80. With the HP-100 steel, you just need about 5-6 pounds less weight. For most people that means you may need from 0 to 6 lbs with no wet-suit. You will always be a little negative at the beginning of any dive when your tank is full, but on a recreational dive you should be able to swim that amount up with no air in your BC. You can also carry an SMB for redundant buoyancy in case of a BCD failure.

Mike

 

[TSandM]

What kind of steel 100 did you buy? Most of them are about -1 when empty, and thus about -8 or so when full. If you have a standard BC with some padding, that means you'll be about 6 or so pounds negative at the beginning of the dive, with no exposure protection. You WILL be heavy and need gas in the BC, but you should be able to swim up six pounds, if your BC were to fail.

However, the Faber 100s which are 7 pounds negative when empty are a different story. That would land you 14 pounds negative when the tank was full, and although some people can swim that up, I suspect others would be unable to do so.

In general, aluminum tanks are a good choice for water water diving with no or minimal exposure protection, because they cycle around neutral, and you don't mind carrying a small amount of weight to counter their positive swing.

 

[Colliam7]

new to diving and picked up a hp100 as recommended for a good overall tank. in just a swimsuit would a aluminum 80 be better? feel like i could dial in my buoyancy in where a hp100 im always going to be heavy and im trying to balance it all on my back. wondering if the hp100 is something you get used to or grab an aluminum?

Could you provide a little more detail about your diving conditions. What are you using for a BCD, etc.? As I read it you have a HP100. What brand? You mention a swimsuit. Are you diving with NO exposure protection? Are you referring to fresh water or salt water? Can you describe your inherent buoyancy - are you positive, negative or neutral in the water?

I think a HP100 is very easy to dive with, but I never dive with anything less than a full 1MM, and usually with a full 3mm. I also have enough bioprene to be slightly positive in fresh water and quite positive in salt water. But, if you are inherently negative, diving only in warm fresh water, using a steep backplate, diving only in a swimsuit, a HP100 may not be the best cylinder for you. Tell us more, inquiring minds want to know.

 

[porkchopexpress]

thanks for the quick responses.

im neutral to slightly negative buoyant
bc is a stiletto
worthington hp100
no exposure protection just swimsuit.

this is doing beach dives/bridge dives at around 30ft saltwater

going to get a few more dives in on the hp tank and see if i can get a feel for it.