Things to know before buying tanks

[uncfnp]

You will get lots of advice, most of it based on each divers preferences and personal experiences. Here's my take:

1) Most divers that dive steel love it, it allows you to remove some of the weight from your belt/BCD.
2) Yoke is fine for HP, that's what we have
3) All tanks, al and steel have to have current hydros and VIP stickers, neither can be filled otherwise, either can fail hydro
4) Many new male divers are "air hogs" you will get better with time. In my experience, most men like 100's to 120's
5) A HP tank will give you the same volume (80, 100 etc) in a smaller package
6) I believe docmartin is referring to the weight of diving doubles. You are buying 2 tanks but diving singles, steel is a wonderful choice.

7) DIN is wonderful. But that means a DIN first stage and can make rentals more problematic.
8) most tanks now come with convertible values that can do DIN or yoke

 

[redacted]

Steel tanks in warm fresh water make me too heavy. Manageable but I have to add an shorty, not for thermal protection, but just to get neutral. I like my HP 100 but I need my Al 80 also.

 

[herr2720]

I bought used which can be a gamble, but so far none of my tanks have failed viz/hydro and the oldest has an original hydro of 1970 (Steel 72). I paid $5-20 for each of them, I like my Steel 98s the best, but at least with a used AL if it fails you can sell it for scrap and get $15-25 back.

 

[GrumpyOldGuy]

I have lived an hour from the shop and know the pain. You more than likely will need 2-3 tanks, not one.
If you only need 1 tank, a steel 100 is the best all around tank, a real sweet spot in size, weight.
The 120/130 are big and heavy, you may not get to use all the air if your buddy has something smaller.
If you need a bunch of tanks, the economics of AL makes sense being just over 1/2 the price of a steel.
The only downside to steel besides high cost is it is slightly more sensitive to wet fills (from a dive boat).

 

[kelemvor]

One of the benefits to having low pressure tanks is you can get better fills. I bought low pressure steel tanks because they hold 108cuft at 2640psi. Most of the time shops fill them closer to 3200 which gives me 144cuft of gas.



I put together this chart when I was trying to decide which tank to get. I will say that having a tank with an 8" diameter is a bit of a PITA on dive boats. Doesn't fit properly into most tank holders. It's never caused me to miss a dive but it's an extra hassle for sure.



You do kind of get screwed if you're boat diving. Most ops insist you head up at 1000psi, which in an al80 is 26.6cuft of air. In my lp108 that's 40.9cuft. Of course, I've never had an op actually check my gas after a dive. Also, now that I have a few more dives logged my SAC rate has dropped and I have to end dives due to reasons other than gas consumption.

 

[toddthecat]

Most ops insist you head up at 1000psi,

Sounds like those ops are a bunch of :turd:s

I've never seen an op play scuba police with air pressure to 1000psi and I certainly would love to see their reaction if they asked to see my gauge (which has never happened). Maybe they do that for the people with low SAC rates to match try and match the air hogs? Either way, most people with good SACs aren't going to listen to some 1000psi limit BS anyway. I paid for a full tank, better believe I'm using more than 2/3 of it...

---------- Post added August 22nd, 2013 at 05:38 PM ----------

And to the original topic: Used is fine. They may be scuffed up but unless you're trying to make a fashion statement, who cares? Tanks get scuffed up, oh well. Get a mesh protector to kind of hide it if it makes you upset. Or one of those crappy plastic slip-on things that you shrink wrap to the tank with a hair dryer. Those will always make you stand out nicely

 

[guruboy]

Newer diver. Closed DS is an hours drive. Know I'm going to stay with the sport and want to pick up tanks to have. My thought process is it takes an hour each way to go pick up rental and drop off. With the cost of gas and daily rental fee I'd be better off purchasing. My research leds me to believe steel is better than aluminum for most. The LDS has steel low pressure tanks for $299 each right now, size was 97cu? I think. I plan on getting two so I have them when the opportunity arrises to go diving and then I'll get them filled next trip that way instead of a special trip. Any suggestions? Am I looking in the wrong direction? Guideance?

FYI - recreational use only.

So you plan to have them filled wherever it is you are diving? And will get any rental gear there as well?

If so, then having tanks will certainly make it more convenient to go diving and save you some gas and drive time.

As far as the tanks go, you won't save much by owning tanks (if any). Each fill saves you like $2-5, before factoring in VIP and hydro costs.

 

[GrumpyOldGuy]

You do kind of get screwed if you're boat diving. Most ops insist you head up at 1000psi, which in an al80 is 26.6cuft of air. In my lp108 that's 40.9cuft. Of course, I've never had an op actually check my gas after a dive. Also, now that I have a few more dives logged my SAC rate has dropped and I have to end dives due to reasons other than gas consumption.

I have never had an op check my gauge either. I have had plenty say be on board with X psi, never had anyone tell me what pressure to ascend on. If they did, we would probably have a interesting discussion on properly calculating rock bottom. I like LP tanks for boat diving, they do suck for shore diving when you have a long hike back to the car.

 

[spectrum]

Newer diver. Closed DS is an hours drive. Know I'm going to stay with the sport and want to pick up tanks to have. My thought process is it takes an hour each way to go pick up rental and drop off. With the cost of gas and daily rental fee I'd be better off purchasing. My research leds me to believe steel is better than aluminum for most. The LDS has steel low pressure tanks for $299 each right now, size was 97cu? I think. I plan on getting two so I have them when the opportunity arrises to go diving and then I'll get them filled next trip that way instead of a special trip. Any suggestions? Am I looking in the wrong direction? Guideance?

FYI - recreational use only.

Having cylinders at the ready will open the doors to more diving in addition to optimizing your fill logistics. If you have everything else then it's a no brainer.

Being in North Carolina you are outside of the swim trunks and dive skin region so the lesser buoyancy of the steel cylinders shouldn't be excessive.

Steel includes low and high pressure cylinders. High pressure, usually 3442 PSI is nothing dramatic, its 442 PSI over the common AL80. High pressure will be the most efficient capacity to total diver weight option. See here. Low pressure will have many of the same advantages, cost less but weight more than the HP equivalent. Other threads beat this to death.

All you really need to do is seed your collection. Once you get going watch CraigsList etc for good deals on used cylinders that may need to be recommissioned. Once you have a few the others can come over time when the price is right. This may mean more cylinders or variety in sizes. You may even have a legitimate need to own a few AL80s especially if you make shallow fresh water dives. They can be warm needing little neoprene or weight.

As a new diver your rate of consumption is worst case and it could plummet over the next few dozen or 100 dives, everyone is different. I caution not to buy entirely to level out your current need. However 100 or 97 CF is a size many, self included enjoy at times so you are unlikely to regret buying that size if you can carry them comfortably. You can always pick up smaller cylinders for less demanding dives when you want to be more nimble on your feet. Likewise for larger.

The only other thing I would mention is that at $299 you are not that far from a HP100 price which has pretty universal recognition as a wcked nice cylinder.

Take your best shot at this and move on. You are not married to them and they do pretty good on resale.

Pete

 

[SVT_Tactical]

All the advise is greatly appreciated.

let me show some of you what I'm reading -
From - Dive Tanks | LeisurePro.com

Scuba tanks are made out of either aluminum or steel. Aluminum tanks are much lighter and less expensive than their steel counterparts. The drawback to aluminum tanks is they are very prone to showing signs of damage, including dings and dents. Steel tanks, while being heavier and more expensive than aluminum tanks, are incredibly tough and tend to have a longer lifespan because of steel's inherit durability. One important note about steel tanks is they can develop rust, so regular maintenance and proper care are crucial.
Steel tanks have been used since diving with tanks was a possibility. As scuba evolved as a sport, aluminum was introduced as a tank material. Because aluminum is softer than steel, the walls of aluminum tanks are thicker than the walls of steel tanks. Therefore, aluminum tanks are a bit larger than their steel counterparts.
Regardless of which material the tank is made from, you'll need to take its buoyancy into consideration when determining how much weight you need on your dives. Most rental tanks are aluminum, so you are probably most familiar with aluminum tanks and how they affect your buoyancy.
It is also important to note that because air has weight, a full tank is heavier than an empty dive tank. Therefore, make sure you wear enough weight to compensate for the additional buoyancy your tank will gain as you breathe its contents.tents.
In the water, an empty steel tank typically weighs about three pounds (negative) and an empty aluminum tank is about 2-4 pounds positively buoyant. This means you'll need to wear more weight when diving with an aluminum tank than when diving with a steel tank. If you've figured out your ideal weight when diving with an aluminum tank, you can typically shed a couple of those pounds if you use a steel tank.
High Pressure vs. Low Pressure

If you've decided steel tanks are your preferred tank choice, you must now decide between high-pressure and low-pressure tanks. A standard aluminum 80 low-pressure tank is 26 inches in length; a standard steel 100 high-pressure tank is only 24 inches long. Two inches may not seem like much, but it is quite a significant difference when the tank is on your back.
High-pressure tanks are smaller than the low-pressure tanks and they contain a greater amount of air. Before thinking that a high-pressure tank is a no-brainer decision, know that high-pressure tanks also require a regulator set up for DIN. If your regulator has a Yoke setup, you'll need to get an adapter to con- vert your Yoke 1st stage to a DIN 1st stage.
Another important note about high-pressure versus low-pressure tanks is service. Because high-pressure tanks are subjected to greater amounts of pressure than are low-pressure tanks, they typically require more frequent servicing and part replacement, especially the valves and O-rings. Because their parts wear out at a faster rate, high-pressure steel tanks are more likely to fail their hydro inspection than are low- pressure steel tanks.
Tank Size