I've been reading about the differences between regulators with balanced/unbalanced second stages.

As I understand it:

Balanced = Easier to breath / More likely to freeflow

Unbalanced = Harder to breath / Less likely to freeflow

Although some balanced regs have controls to allow you to adjust air flow.

For those with their own regs, can I ask which you use and why?

I have oceanic Alpha 8/ CDX5, 1st/ 2nd stages

Main reason was price, but I do like them. They breath well at any depth (max depth I've taken them is 30m so far) and regardless of the tank pressure. works with both air and nitrox. They did seem to come out well in most budget reviews I read too. They are only just coming up to their first service though so not sure about durability. They have had some hard use and only had to replace one mouthpiece on the two sets the mrs and I use. I did have 1 free flow during 6 dives in 5C.

Next time I'd probably invest in a more advanced second stages with a venturi control.

I have Oceanic Alpha 8 first and second.

Very reliable, they were cheap and I got them in a set with a BCD, which I haven't used yet. I can't afford diving at the moment and hate asking my parents for money lol. I also thought for my first set of regs, I wanted something a bit hardy and Oceanic's lifetime warranty was a bonus.

Are the Alpha 8s good for cold water diving then, would you say?

Balanced for primary/back gas, un-balanced for stages.

When you're diving you need to be able to breath easily, any restriction will cause you to work a little harder on every breath. You will use a little more air and generate a little more CO2 (CO2 = not good). A balanced reg will supply plenty of air at all depths. I have been using Mares MR22 1st with Mares Abyss 2nd stages for years. I did my Adv Trimix in 2003 (had been using it for 2 years then) with the Abyss and was asked by my instructor what I thought. I told him they were an excellent breath and he then used them to dive to 313m!! I still have the same regs which I use on every OC dive (424 last year). They will freeflow if you take them out and turn them front down, they are supposed to, most regs will. As it's in your mouth when you jump in it won't happen.

What you don't want is for the cylinders you're not breathing to freeflow, unbalanced regs are ideal for this. You'll notice the difference when you switch between the two.

I now have 4 Abyss regs, bought the rest on ebay for about £70 a set. I service them myself and have not had any problems with any of the regs. They are good in Cold water i.e. below 10 degrees.

I have 20+ regs, no Oceanics though.

p.s. If you guzzle air a balanced reg won't help, it'll help you guzzle the air easier. Some people prefer unbalanced as it can make your air last longer. If you go into panic an unbalanced reg will feel like it's restricting your breathing and make the whole problem feel worse.

thetafferboy wrote:


They are not really designed for cold water. I got mine for warmer waters (10C+). I never thought I'd be mad enough to dive in water that cold . The ones I used at stoney were school owned, but they performed ok apart from the 1 free flow that wasn't that bad.

I purchased the Aqua Lung Titan LX Supreme. This is also very good for cold water diving, perfect for the cold waters of Canada.

In Canada I paid S499.99 for the package.

When the VAS is set to the maximum (+) position, the regulator will provide maximum venturi assistance. This makes it easier to breathe at deeper depths and increased work loads. For normal sport diving conditions, the regulator will perform suitably if it is left set to the minimum (-) position. This setting will also help to prevent the second stage from free flowing during entry or while swimming on the surface.

From the Mares website.

All that performance and I've never had a freeflow.

When I purchased this regulator (2009) I knew nothing about diving and was told that this is what I needed.

I didn't even know what a freeflow was.

Having said this, I have seen others waiting on the surface for a buddy or something else and their regulator dangling down in the water started to freeflow. Maybe this is what Aqua Lung meant.

I know this is not the same as underwater freeflow with the regulator in the mouth.

Regulator 2nd stages have a 'crack pressure' This is the negative pressure required within the regulator to start to supply gas. The lower the crack pressure the more likely to freeflow if used left dangling etc. Placing your 2nd stage face down in a bucket will demonstrate this, mine is set at 1.25" before it releases gas. That's 1.25" from the front of the purge button.

thetafferboy wrote:


Well I used mine in Vobster in October and it was fine! I also know that the National Marine Aquarium use them permanently in their Atlantic reef exhibit, which is cold water and as far as I no they have never had any problems. Hopefully I will be using mine more over the summer so will be able to let you know, if I have any problems!

tropical_shark wrote:

What was the temp in Vobster in October?

The NMA will be cold water but what is the water temp? I doubt it'll be under 10 degrees.

Do not expect any reg not stated as a cold water reg to work under 10 degrees indefinitely. Regs that are not cold water rated can freeze up, your breathing compressed air which takes heat from it's surroundings when it expands. You've seen a cylinder valve when you let air out quickly, it'll gain ice in the summer. In cold water this can cause the 1st stage to freeze, especially if you are breathing a little heavier due to the cold conditions.

The problem is greater with Helium in the mix as that require more heat to expand.

There's too many people who've had un-explained freeflows resulting in a bad outcome to try it.

Any reg should be fine down to 10 degrees but you need a cold water reg to go below that safely.

AtlanticScuba wrote:
Any reg should be fine down to 10 degrees but you need a cold water reg to go below that safely.[/quote]

So assuming I'm doing some cold water diving, I guess better to get a cold water reg and use that in warm water too? Can't afford 2 regs just yet!

thetafferboy wrote:

If you intend to dive in water below 10 degrees then yes, a cold water reg is needed. Cold Water regs have more metal or have fins to help abosrb heat from the surroundings to stop them from freezing. If anything, cold water regs are usually better regs and will work in any temperature water you can be in.

i have mares proton ice extreme-octopus proton ice extreme . i think i had a good deal £475 .but they feel realy good

With my Aqua Lung Titan LX Supreme I dived at a temperature of 3 degrees Celsius. Most regulators sold in central Canada take cold water into account. I'm told that you can use it in even colder water. I would check with the manufacture before ice diving though.

I also used it in my last trip to Key Largo, Florida at 30 Celsius.
I am very happy with my regulator.