Buying a tank, if you don't know what you're buying

[2airishuman]

Thanks for the replies. I've read through a bunch of reviews of pros cons of aluminum/steel and various tank sizes but am not sure what would be best for me. Here's my situation:

• I've only ever dived AL80s. The buoyancy issues people cite for aluminum tanks haven't bothered me.
• I have always ended dives because I run out of air instead of bottom time
• I'd like to do this on a budget, but if a better solution is a bit more money, that's ok
• I'm not currently Nitrox certified but intend to get certified

What kind of tank (or tanks) would you recommend I buy?

As a very general rule, if you are of medium build and have been happy with AL80s, you would probably be even happier with HP100s. They are a good choice for most people, with essentially the same size and weight as AL80s but slightly greater capacity. The last ones I bought were $200 from a local seller and were in hydro, great shape, only a year old. That was a pretty good deal. Check Dive Gear Express's pricing and subtract out the cost of a hydro and VIP and whatever the hassle and condition of a used cylinder are with to you.

There are two LP85 Faber steel tanks with plus rating for sale in my area, with inspections through 2018 and 2019. $300 for the pair, with offers accepted. Would these be a decent option, and what's a reasonable price?

I have an LP85 Faber and it's a nice cylinder. Sort of an updated LP72, a little taller and a little higher pressure to give some more capacity. Close to neutral buoyancy when empty, which is ideal. $300 for a pair is a fair price for a pair if they're in good shape and in hydro.

 

[BRT]

As a very general rule, if you are of medium build and have been happy with AL80s, you would probably be even happier with HP100s. They are a good choice for most people, with essentially the same size and weight as AL80s but slightly greater capacity. The last ones I bought were $200 from a local seller and were in hydro, great shape, only a year old. That was a pretty good deal. Check Dive Gear Express's pricing and subtract out the cost of a hydro and VIP and whatever the hassle and condition of a used cylinder are with to you.



I have an LP85 Faber and it's a nice cylinder. Sort of an updated LP72, a little taller and a little higher pressure to give some more capacity. Close to neutral buoyancy when empty, which is ideal. $300 for a pair is a fair price for a pair if they're in good shape and in hydro.

30% more capacity is not slight.

 

[Tug]

There are two LP85 Faber steel tanks with plus rating for sale in my area, with inspections through 2018 and 2019. $300 for the pair, with offers accepted. Would these be a decent option, and what's a reasonable price?

As a local diver, I'd go for the 85's. I find tanks like 85's or 100's to be great for shore diving locally and they are great for boat diving if you decide to hit a somewhat deeper site.

As for the price, I'd be comfortable paying the asking price or maybe slightly less. In fact, I know some people that would probably snatch them up if you don't

 

[halocline]

There are two LP85 Faber steel tanks with plus rating for sale in my area, with inspections through 2018 and 2019. $300 for the pair, with offers accepted. Would these be a decent option, and what's a reasonable price?

This could be an excellent deal. LP85s are very popular for double sets because they are a bit narrower and have excellent buoyancy for doubles (neutral empty). $150 each is a very fair price if they are good condition. If there were a good pair of LP85s available here for $300 I would be tempted to buy them, even though the last thing I need is more dive gear.

I have never bought a new cylinder; there are always good deals to be found on used cylinders, and unless they are visibly damaged, they rarely have any problems. But there is a slight risk with steel tanks, if you can't look inside them. They can rust on the inside from water intrusion, usually from a faulty compressor or careless fill operator. So it's a good idea to be able to remove the valve, and look inside with a small light. You don't have to be an expert; you'll either see rust or you won't. Some light surface rust is ok, but big spots of deep-looking rust spell death for a steel tank.

Aluminum cylinders, less than 20 years old, are almost entirely risk-free to purchase. Unless they've been badly abused, they almost never fail hydro. Many shops will simply refuse to fill older AL tanks out of fear of the older alloy. It takes some knowledge to be sure which tanks have the older alloy, and many shops don't want to deal with it, so they tell their minimum-wage tank fillers to not fill any tanks older than (x) years.

If you're really looking for a bargain, you might consider some LP72s. They have great buoyancy and are a breeze to carry around for shore diving. You can often find them for under $50. You won't get really deep dives out of them, but for shallow shore dives around here they're perfect.

One last bit of advice, avoid AL100s like the plague. They are without a doubt the worst scuba tanks made. They weigh a ton, are huge, with poor buoyancy characteristics, and to top it off many shops under-fill them.

 

[Mr. Manfrenjensenden]

Thanks for all the advice. Ended up buying the two LP85s. Guy who sold them was helpful and answered a bunch of questions.

Two more questions, though:

• Other than rinsing off the tanks after a saltwater dive and making sure the boot drains well, what kind of regular preventative maintenance should I do in between visual/hydro?
• I know how much weight I need when diving in salt water with a 3/2mm full suit with 5mm booties (no hood/gloves) and an AL80. How much less/more weight will I need diving in salt water with a 7mm full suit with 7mm booties/hood/gloves and a LP85 tank?

Thanks,
Peter

 

[Jim Lapenta]

Don't let them get empty. That's about all the PM you need to do. Check the o rings if they are yoke valves.
There's no way to tell that without an actual buoyancy check.
Anyone who says different is just pulling numbers out of their nether regions. Suit brand, age, your height, weight, etc. all play in. The only thing I can say is it's not going to be less. Just because it's twice as much neoprene for one thing. I need 8 lbs in a 3 mil in salt with an al80. LP 85 in a 5 mil that's 6 years old or so I need 10. 7 mil? No idea since if it's cold enough for a 7 mil I'm diving dry. :=)

 

[teknitroxdiver]

Thanks for all the advice. Ended up buying the two LP85s. Guy who sold them was helpful and answered a bunch of questions.

Two more questions, though:

• Other than rinsing off the tanks after a saltwater dive and making sure the boot drains well, what kind of regular preventative maintenance should I do in between visual/hydro?
• I know how much weight I need when diving in salt water with a 3/2mm full suit with 5mm booties (no hood/gloves) and an AL80. How much less/more weight will I need diving in salt water with a 7mm full suit with 7mm booties/hood/gloves and a LP85 tank?

Thanks,
Peter

Awesome! I think you'll be very happy with them.

Rinsing is about all you need to do. It's good to take the boots off the tank when you rinse and leave them off until the tank is dry. And if you can survive without the boots at all, that would be better.

You'll have to do a dive to figure out the weighting. Too many changes to calculate it. If you weren't changing anything but the tank, you could drop 3 or 4 pounds, but with the suit change who knows.

 

[Mr. Manfrenjensenden]

Don't let them get empty. That's about all the PM you need to do.

Does empty mean completely empty? Is a few hundred PSI at the end of a dive ok to store them for a bit?

 

[teknitroxdiver]

Does empty mean completely empty? Is a few hundred PSI at the end of a dive ok to store them for a bit?

Yes, that's fine. Just not completely empty.

 

[JamesBon92007]

Does empty mean completely empty? Is a few hundred PSI at the end of a dive ok to store them for a bit?

I had a DM at Cozumel get all upset with me because I surfaced with only about 350 psi left and he was going to have to "take the tank apart and clean it all out" or something to that tune. Back when we dove with J-Valves they weren't even activated until 300 psi and most divers I knew figured 100 psi was a good amount to have left in the tank. Now it seems to be 500 psi but the way I see it is that no water can possibly enter if there is compressed air in it. I almost always stopped at the dive shop on the way home and got my tank filled so it was never empty for long. That turned out to be a bad idea when I got my first aluminum tanks--years later they discovered that "sustained load" was ruining the tanks. That does not seem to be the case with steel tanks.