Question Diving with steel tank questions.

[Brent Bowman]

I dive on the Kona Coast in Hawaii and use pretty much the same gear all the time. I have been using my own dive gear with rented aluminum 80 cf tanks with about 17 pounds of weight and everything seems to be working pretty well with this setup as far as I know anyways. I'm about 6' tall and weigh around 185 lbs.

I decided to buy my own tanks and figured if I was going to do it I may as well get good ones, so I ordered two Faber XS Scuba HP 100 HDG steel tanks with the Pro Valves.

So, if I have been happy with using 17 lbs of lead and rental aluminum 80 cf tanks, about how much weight should I start with for my new HP 100 cf steel tanks? I just want some input\opinions on a good starting point and then I can experiment with my buoyancy from there.

Another quick question is that I use an Aqualung Mikron regulator with a Yoke connection. Is my Mikron regulator with Yoke Connector going to be OK to use on my new steel tanks at 3442 PSI even though the Mikron specs say 3300 psi max with a Yoke connector? I have heard it will be fine, but would like more opinions. I believe I could switch the regulator over to a DIN connection, but it would be alot more convenient to keep the Yoke Connector so I can use rental and friend's tanks also.

Thank you, I appreciate any input on using my new steel tanks, and hope to meet some of you diving one of these days.

Thanks again,
Brent Bowman

 

[inquis]

Luxfer AL80s buoyancy is +4.4 lb, and the Faber HP100 is -0.6 lb. Therefore drop 5 lbs of lead if that's the only thing you're changing. The AL tanks *might* be Catalinas, which are slightly less buoyant, but try diving with 12 lbs and evaluate whether there's air in your BC at the end of the dive with 500 psi at the safety stop. (Purge your tank if needed.) If there is, drop another 2 lb and test again on the next dive.

 

[MaxBottomtime]

You will need about five pounds less with the steel 100. I prefer a DIN valve so I don't have to worry about the O-Ring popping out. I can use a yoke adapter if I use an aluminum tank.

 

[Gone for diving]

I usually say aluminum 80 to steel 120. 3 - 5 lb less... and tweek from there..

 

[Litefoot]

I dropped from 20 lb to 10 lb when I switched from AL80 to HP100. But then, I may have been overweight a little before making the switch. You will love the difference diving with steel tanks. Good move.

 

[tursiops]

Second question: no problem. The DIN insert for your PRO valves will do the trick. You are not likely to get 3442 fill anyway!

First question: the steel tank will be maybe 6 pounds heavier in the water than the AL. But it is also bigger: the HP100 holds about 8 lbs of air, whereas the AL 80 only holds about 6 lbs. If you dive both tanks down to the traditional 500 psi or so, the larger tank will have lost some 7 lbs of gas versus the 5 lost at the end of a AL80 dive. I'd start by dropping your 17 lbs down to 10-12 lbs.

 

[inquis]

I dropped from 20 lb to 10 lb when I switched from AL80 to HP100

It's pretty cool how one can improve without even realizing it. When you then tested (in the context of a new tank), you got to drop even more than the tank warranted. Not exhaling fully is perhaps the #1 sign of anxiety. Congrats on your improvement!

 

[Seaweed Doc]

I usually see a 6 pound difference going from a steel to aluminum, but that may be the details of my steel tank (HP 120)

 

[MaxBottomtime]

SCUBA Cylinder Specifications – Huron Scuba, Snorkel & Adventure Travel Inc. PADI 5 star IDC in Ann Arbor, MI

huronscuba.com

 

[lowwall]

Your new tank is 5lbs less bouyant than an AL80. So start there.

But I suspect you are currently heavily overweighted, so do a real weight check during your safety stop. Let all the air out of wing, stop moving and slowly exhale. If you start sinking and a regular inhale doesn't stop it, take a pound off on your next dive and repeat.

Also, your yoke valve will be fine at 3442psi (if you are lucky enough to find a shop to fill it that high). The highest pressure fill I've gotten is from Aldora in Coz.

No problem with my 20 year old yoke regs. Aldora has led tens of thousands of dives with yoke regs at these pressures without issue.