15l tanks

[flyboy08]

Again my math might be a bit fuzzy, but if IRCC Aldora only charges about $10 for nitrox so your Al 100 for $30 vs steel 120ies for $20 doesn't seem a wash to me. Not to mention, if your "100s" are filled to:
psi-----cu ft
3000 = 90
3100 = 93
3300 = 100

Thanks, but we’re committed with ProDive at our resort....I don’t fret over a few bucks as much as I do over a few psi.

I’m told a ProDive has to rent the 15L tanks...from who, I don’t know.

 

[BRT]

Generally (I think probably always) the service pressure is 3300 PSI.

So you understand why it may not be as simple as one might think to get that fill:

Tanks at all but the smallest operations are probably not filled one at a time, with someone monitoring the PSI. There are banks of multiple fill whips attached to rows of tanks, and a regulator in the line that is set to stop the fill at a certain pressure, probably 3000. With the regulators that I am familiar with, even temporarily adjusting that regulator up to a higher (or lower) pressure is not as simple as turning the dial to a preset position. It takes a little more effort to zero in on the desired set, and then the same effort to return it where it was.

Now, even if you have a fill station that makes that effort, or does enough 3300 fills to have a separate line with a regulator set for that pressure, you will also have an issue with the PSI falling a bit as the warm/hot tank fill cools down. Again, is the operation taking the time to go back and top off, or just leaving it at a "close enough" value? While I am sure many operations overfill in anticipation of the tanking cooling down to about where it should be, topping it off is the "by the book" method and no one should be faulted for following it.

The nice part about this is that LP tanks may accidently get filled to 3K# too.

 

[scubafanatic]

What is the max psi for an aluminum 100/15L? I'm paying $15 a tank for this privilege, and I better get decent fills.

From my experience the big central fill station that services most dive ops doesn't care AL80 vs AL100, consider yourself blessed if you even get 3000 psi in anything, they are in a high speed/mass production mode and don't have time/interest in distinguishing between AL80 @ 3000 psi vs AL100 @ 3300 psi, they sure as heck don't have time/interest in allowing 'hot' fills to cool off and come back and do a 'top off' either. The handful of boutique/premium dive ops that do their own in-house fills are your only hope of getting genuine 'full' fills. On a liveaboard I have easy access to the tank fillers to express my wishes in this regard with $ tips as appropriate.

 

[scubafanatic]

The nice part about this is that LP tanks may accidently get filled to 3K# too.

Low pressure 'steels' are very rare in Coz, Living Underwater is the only shop I've heard of using those. Many years ago (like 15 yrs ago) Dive with Martin could provide LP 95's for extra $, I don't remember ever getting juicy fills on those either.

 

[ggunn]

From my experience the big central fill station that services most dive ops doesn't care AL80 vs AL100, consider yourself blessed if you even get 3000 psi in anything, they are in a high speed/mass production mode and don't have time/interest in distinguishing between AL80 @ 3000 psi vs AL100 @ 3300 psi, they sure as heck don't have time/interest in allowing 'hot' fills to cool off and come back and do a 'top off' either. The handful of boutique/premium dive ops that do their own in-house fills are your only hope of getting genuine 'full' fills. On a liveaboard I have easy access to the tank fillers to express my wishes in this regard with $ tips as appropriate.

FWIW, on my last trip to Cozumel where I dove 20-25 AL80 tanks I only had a couple of them that were filled to less than 3000psi by the fill station; usually they were at 3100-3200psi. Both times the DM switched tanks with me so that I had 3000+psi.

 

[Dave Dillehay]

From my experience the big central fill station that services most dive ops doesn't care AL80 vs AL100, consider yourself blessed if you even get 3000 psi in anything, they are in a high speed/mass production mode and don't have time/interest in distinguishing between AL80 @ 3000 psi vs AL100 @ 3300 psi, they sure as heck don't have time/interest in allowing 'hot' fills to cool off and come back and do a 'top off' either. The handful of boutique/premium dive ops that do their own in-house fills are your only hope of getting genuine 'full' fills. On a liveaboard I have easy access to the tank fillers to express my wishes in this regard with $ tips as appropriate.

Aldora is the only HP High Capacity tank operation that has their own fill station to assure proper fills.

Dave Dillehay

 

[scubafanatic]

FWIW, on my last trip to Cozumel where I dove 20-25 AL80 tanks I only had a couple of them that were filled to less than 3000psi by the fill station; usually they were at 3100-3200psi. Both times the DM switched tanks with me so that I had 3000+psi.

Also bear in mind your reported psi readings are well within variations in instrument calibration, some folks have 'optimistic' gauges/computers.

 

[Dave Dillehay]

Also bear in mind your reported psi readings are well within variations in instrument calibration, some folks have 'optimistic' gauges/computers.

Dear Scubafanatic,

Being an instrumentation engineer for many years, I was thinking of bringing that up. Almost never are any two gages in perfect agreement…even very expensive laboratory ones which are much better than the ones bounced around with scuba gear. So some who think they always get short fills, or over fills, may more properly blame their own gages—and digitals are no better.

The same very basic concept of instrumentation holds true for water temps which would probably explain some conflicts on that issue. Indeed who really should expect their water temp readings to be better than plus or minus 2-3 F.


Dave Dillehay

 

[MrBigfins]

Having dove with prodive a couple times using the 15l tanks, I will offer my input. Prodive at allegro fills their own tanks, and NEVER to 3300 psi. After a few tanks at sub 3k and complaining, I talked to the guys who fill the tanks and managed to get cooled tanks at 3k. I found that the best system was to simply use 15l tanks for the first deeper dive and an 80 for the second dive. I'm 6'7 and 250ish, so I use my fair share of air. The 15l let me get 60-70 min+ on deeper dives and still got 60ish min on the 80 for the shallower dives.

If you have a good group and plan to do a number of dives, talk to Nacho early in your trip about a Punta sur dive. One of my favorite sites, but prodive isn't too keen on taking random groups there and it is never on the official schedule. Tormentos is a great dive for the second dive and one of my other favorites.

Remi, Leo and Roland were some of our favorite DMs this last trip. Tell them that Mike, Cheri, Christian, Wade and Amy said hi. All 3 are laid back and will work with your group on preferences. Try to talk Angiei going on a dive with you, she will love you for it (ps take her an ice cream cone). Enjoy yourselves and be safe

 

[MrBigfins]

As for weighting difference, I used about 2lbs less with the 15l. I use a 1.75lb ankle weight on the tank neck of an 80 and just ommited it for the 15l. Make sure to get an end seat space to accommodate for the extra space needed for the 15l tank. Use 2 tie offs to keep it stable since you can't use both sides of the tank holders.