Balanced 2nd Stage with Unbalanced Alternate

[5hundo]

Hey folks...

I was talking to a guy at the dive shop about my octo, and said that I was running an Aqua Lung Legend, with an Aqua Lung ABS alternate. He told me that I might have problems with this setup, since the Legend is a balanced reg, and the ABS isn't. Is this something I should be really worried about? I have a vague concept of what the difference is but no idea why they would conflict with each other.

Thanks for your help!!!

 

[Tony387]

Nothing wrong with that at all. He's full of it...trying to sell you another reg.

Sent from my SCH-I545 using Tapatalk

 

[underH2Oman]

They will not conflict with each other.
A balanced second stage is designed to breath just as well at depth as it does in shallower water. A non balanced will get slightly harder to breath at depth than shallow, but the depths that it generally becomes noticeable are well beyond recreational depths.

 

[Luis H]

The balanced (primary) second stage is irrelevant to the performance of the octopus.

What he might have been talking about (and probably was, but didn't explain it well) is that the first stage is what they call over-balanced. This feature actually has nothing to do with balanced design, but that is what they call it.

What the over-balanced design does is that the depth/ pressure compensation of the first stage is biased to increase the IP (intermediate pressure) with depth at a rate higher than just the normal pressure compensation of most regulators. The intermediate pressure, above ambient pressure, will increase the deeper you go.

In theory this could translate into a non-balanced, basic downstream, second stage to free flow in deep dives. In practice, it should not be an issue for most recreational depths, unless the octopus was adjusted to be very sensitive (which is not a good idea for an octopus anyway).

 

[5hundo]

The balanced (primary) second stage is irrelevant to the performance of the octopus.

What he might have been talking about (and probably was, but didn't explain it well) is that the first stage is what they call over-balanced. This feature actually has nothing to do with balanced design, but that is what they call it.

What the over-balanced design does is that the depth/ pressure compensation of the first stage is biased to increase the IP (intermediate pressure) with depth at a rate higher than just the normal pressure compensation of most regulators. The intermediate pressure, above ambient pressure, will increase the deeper you go.

In theory this could translate into a non-balanced, basic downstream, second stage to free flow in deep dives. In practice, it should not be an issue for most recreational depths, unless the octopus was adjusted to be very sensitive (which is not a good idea for an octopus anyway).

Yeah, that's pretty much what he was saying. If I went deep, it could cause a free flowing reg, or something. Thanks for clarifying it for me guys!

How deep are we talking here? I rarely go under 110 feet but I'm looking to get my wreck cert, so I might go a bit deeper in a few months. Is it worth it to change it out?

 

[herman]

Its going to be at 100+ unless the octo is adjusted close to the edge (an octo shouldn't be). That said, the ABS is a poor excuse for a reg....it will work but its poor quality. You would be much better served with an older used (but serviced) octo.

 

[ams511]

A balanced second stage is designed to breath just as well at depth as it does in shallower water. A non balanced will get slightly harder to breath at depth than shallow, but the depths that it generally becomes noticeable are well beyond recreational depths.

Balancing deals with tank pressure not depth. All regulators are depth compensating. If you dive an unbalanced combination say a MK-2/190 or a Calypso you will notice that at the end of the dive when the tank is near empty it is harder to breath than when the tank is full. Where if you are using a balanced combination say a S600/MK-25 or a Legend you will not notice a difference in breathing regardless tank pressure.

All regulators will breath worse at depth because the gas is denser. This is more pronounced in unbalanced regulators because they are cheaper and lower-performing.

---------- Post added April 27th, 2014 at 10:29 PM ----------

That said, the ABS is a poor excuse for a reg....it will work but its poor quality. You would be much better served with an older used (but serviced) octo.

I have to agree the ABS sucks. Prime Scuba was doing a close out on Kronos octos that would be a better choice.

 

[ron_dodge]

Hey folks...

I was talking to a guy at the dive shop about my octo, and said that I was running an Aqua Lung Legend, with an Aqua Lung ABS alternate. He told me that I might have problems with this setup, since the Legend is a balanced reg, and the ABS isn't. Is this something I should be really worried about? I have a vague concept of what the difference is but no idea why they would conflict with each other.

Thanks for your help!!!

I agree with most people that this shouldn't be a problem. My wife and I have almost the exact setup. We have an Apeks Tungsten (XTX200) first & second stage with a Sherwood Minimus octopus. The Apeks is an overbalanced reg and the Minimus is an older octo that is not balanced.

We've been down to 108' without issues.

 

[keyshunter]

I agree with most people that this shouldn't be a problem. My wife and I have almost the exact setup. We have an Apeks Tungsten (XTX200) first & second stage with a Sherwood Minimus octopus. The Apeks is an overbalanced reg and the Minimus is an older octo that is not balanced.

We've been down to 108' without issues.

Interesting that you say that. At one point I had a Minimus (not for long), and it is one of the few octos I tried that I thought breathed worse than the Aqua Lung ABS.

 

[BoltSnap]

AL doesn't recommend this combination as far as I know. I wouldn't second guess the manufacturer.