Can I Use Double Cylinders for Aqualung Pro LT

[tbone1004]

My instructor/owner of my LDS told me not to mess with steel tanks. Why do you recommend them? He didn't give me much reason other than they can corrode and rust easier than and AL tank.

let's see.
AL80 weighs about 32lbs empty, and contains 77cf of gas. It requires 4.4lbs to make it neutral, and is 26" long x 7.25" in diameter
Faber FX100 weighs 34lbs empty, contacts about 110cf of gas, is half a pound negative, and is almost exactly the same dimensions.
So you have a tank that is 3lbs lighter on land for a rig weight *2lbs heavier, but 5 less pounds of lead required to make it sink* that holds 40% more gas in the same size package. Much more efficient.

Do they rust? They can if you don't take care of them, but if you fill them properly and rinse them properly they will last much longer than an aluminum cylinder and are overall much better. Diving primarily salt water means you should look for hot dip galvanized tanks if you can and if you get something like say a Worthington 100, it holds a true 100cf, but is 2" shorter than the Faber but is 1lb lighter and is 2lbs more negative so you can take an extra 2lbs off of your weight belt which is quite nice and the total rig weight ends up being 6lbs lighter than an AL80 with 30% more gas. That's not a bad deal especially if you are considering going to doubles just to extend bottom time

 

[Diver0001]

I've looked through the owners manual and it says
"Aqua Lung does not offer a twin cylinder kit for your BC. If you want to adapt twin cylinders to your BC, you must consult with your professional dive retailer about after-market twin band kits that would work with your specific model.

Before adapting your BC for use with double cylinders, it is important to compare the lift capacity of your particular BC size and model with the buoyancy specifications of the cylinders, the amount of weight you will carry, and the type of exposure suit you will wear."

This leads me to believe that it is possible. I would like to get a backpack or wing style BC at some pont, but I just got this one so I would like to get at least a year out of it before I go and buy something that is made for doubles.

What, if any, options do I have for double tanks? Should I try to find a way to hold 2 tanks on my back or would I be better of wearing one on my back and one sidemount? I would really appreciate any help. If my logic is messed up here I would really appreciate a correction there as well from someone with more experience than I (which is probably 99.9% of you)

Don't. It will be very unstable with twin tanks and BCD's like this can't take the weight. Using twin tanks on it will shorten it's life span. If you want to dive with twin cylinders then you ideally want a BCD that was made for that specific purpose.

R..

 

[Bent Benny]

Just so everyone knows for further replies, I'm not going to use twin tanks right now and definitely not with my current bc. It seemed like it might be.my best option but after talking with you guys I'm thinking differently about it now.

 

[eelnoraa]

Still, I agree with other. If when you decide to go doubles, don't even bother to try to convert any conventional BCD to take double. Even if you make it, it is a half bake solution. Just spend the money to get a backplate and a proper size double wing at that time. This piece of equipment will last you a lot longer in your diving career.

In fact, if you have such a plan, buying a backplate and single wing now isn't a bad move. The backplate is needed anyway. So you extra cost is just a single wing now. And sell your BC.

Especially if you are in cold water, steel tank is the way to do. Dive shops don't want to sell backplate or steel tank to new divers because they do, they won't be able to sell the "upgrade" later.

 

[Bent Benny]

should have at least an hour at 30-55...

I'm having a really hard time doing this. I've dropped 14 lbs of ballast and have been monitoring my breathing very closely, trying to breathe slow and deep. Still I am only getting about 30 minutes from 3000psi to 500psi.
The only things I can still think might be keeping me from getting an hour are
1. I have been a heavy smoker for about 12 years. About a year ago I quit and started vaping which has helped my lungs, but they still aren't perfect. I am in the process of weening myself off vaping because I don't want it to interfere with my diving.
2. I am fairly cold in the water. It's bearable and not bad enough that I don't enjoy myself, but I am usually tense and slightly shivering while doing my safety stop. (drysuit on it's way)
3. I fin fairly hard. My instructor told me after he certified me that I should slow myself down because I zoom around too much down there. I've tried to do this but I just feel most comfortable when I kick a little hard. Also there has been a decent amount of current at most of my dive sites so I usually have to kick somewhat hard.

Which of these things do you think is the biggest contributing factor? Do you have any advice to help me get more out of my tanks? Are there any resources online that you would recommend that I check out?

 

[Searcaigh]

How's your buoyancy?

Mastering buoyancy will noticeably decrease your air consumption

 

[Compressor]

I'm having a really hard time doing this. I've dropped 14 lbs of ballast and have been monitoring my breathing very closely, trying to breathe slow and deep. Still I am only getting about 30 minutes from 3000psi to 500psi.
The only things I can still think might be keeping me from getting an hour are
1. I have been a heavy smoker for about 12 years. About a year ago I quit and started vaping which has helped my lungs, but they still aren't perfect. I am in the process of weening myself off vaping because I don't want it to interfere with my diving.
2. I am fairly cold in the water. It's bearable and not bad enough that I don't enjoy myself, but I am usually tense and slightly shivering while doing my safety stop. (drysuit on it's way)
3. I fin fairly hard. My instructor told me after he certified me that I should slow myself down because I zoom around too much down there. I've tried to do this but I just feel most comfortable when I kick a little hard. Also there has been a decent amount of current at most of my dive sites so I usually have to kick somewhat hard.

Which of these things do you think is the biggest contributing factor? Do you have any advice to help me get more out of my tanks? Are there any resources online that you would recommend that I check out?

First I want to congratulate you on quitting your smoking habit. Its NOT easy to do and you deserve tremendous credit for it. Seriously Bravo to you.

As you dive more, you will get better. Biggest factor to help your air consumption is to slow down. Slow slow slow does it. Wear adequate protection and then you will be warm and relaxed and then slow down. It will all happen.

 

[BrianF]

Movinn slowly has made the biggest difference for me in my air consumption. I was always in a hurry when I started diving, no I realize I can actually see a lot more moving slowly.

I dive in cold water all the time so the first tanks I bought were steel tanks. I looked around on Craigslist until I found some steel tanks 100 cuft or larger and then picked them up for about the same price as new aluminum tanks. Now I have more air and have to carry less lead with me. It was one of the best dive gear investments I have made.

 

[tbone1004]

@Bent Benny
30 minutes at that depth is about 1cfm give or take, that's really high.

smoking doesn't matter for SAC rate, the best sac rate I've ever witnessed is from a heavy chain smoker. It's obviously not good for you and agencies like GUE won't actually teach anyone who's a smoker because of a myriad of reasons but top of the list is poisoning yourself with CO if you smoke right before you dive, but it shouldn't really hurt your sac rte.

cold water can hurt your sac rate, but only if you let it. You burn more energy in cold water but don't inherently need to breathe faster it's just a natural response. Learn to control it and it will help. My SAC is actually lower in cold water as I let my whole body slow down which helps. Cold water treatments at the surface just prior to your descent will help immensely. Probably good for 0.2cfm

moving around is the biggest contributor. If you're a bit of a spaz underwater, you are going to breathe like one. Look at the animals in the water and try to act like them. They all kind of lazily meander around to conserve energy and only bolt if they have to. While you may be in high current, learn about the currents and work with them. Start your dive into the current, then when you have exhausted half of your gas supply *minus your reserves, so ends up being about a third*, let the current bring you back to where you came from. Don't try to fight it the whole time. That is worth a lot and is definitely going to be the biggest contributor in you sucking gas like a hoover

 

[Bent Benny]

How's your buoyancy?

Mastering buoyancy will noticeably decrease your air consumption

It's getting much better especially now that I have dropped some ballast. Yesterday when I dove I put a tiny bit of air in my bc at depth then didn't really need to touch it until ascent.

@Bent Benny
30 minutes at that depth is about 1cfm give or take, that's really high.

smoking doesn't matter for SAC rate, the best sac rate I've ever witnessed is from a heavy chain smoker. It's obviously not good for you and agencies like GUE won't actually teach anyone who's a smoker because of a myriad of reasons but top of the list is poisoning yourself with CO if you smoke right before you dive, but it shouldn't really hurt your sac rte.

cold water can hurt your sac rate, but only if you let it. You burn more energy in cold water but don't inherently need to breathe faster it's just a natural response. Learn to control it and it will help. My SAC is actually lower in cold water as I let my whole body slow down which helps. Cold water treatments at the surface just prior to your descent will help immensely. Probably good for 0.2cfm

moving around is the biggest contributor. If you're a bit of a spaz underwater, you are going to breathe like one. Look at the animals in the water and try to act like them. They all kind of lazily meander around to conserve energy and only bolt if they have to. While you may be in high current, learn about the currents and work with them. Start your dive into the current, then when you have exhausted half of your gas supply *minus your reserves, so ends up being about a third*, let the current bring you back to where you came from. Don't try to fight it the whole time. That is worth a lot and is definitely going to be the biggest contributor in you sucking gas like a hoover

What is a cold water treatment? I have started wetting my wetsuit before I put it on as someone on here suggested that.