Question Using an Octo as a primary reg

[DiverDave65]

Thinking of buying a Mares Ultra adj Octo and using it as a primary reg. Any thoughts?? I recently bought a Mares Adjust octo and it is easily the best octo I have ever owned, as far as ease of breathing!

 

[lowwall]

Go for it. The only difference between Mares primary and octo versions of the same second stage is the yellow cosmetics.

 

[Nemrod]

Thinking of buying a Mares Ultra adj Octo and using it as a primary reg. Any thoughts?? I recently bought a Mares Adjust octo and it is easily the best octo I have ever owned, as far as ease of breathing!

Typically an octopus is set up slightly stiffer, higher cracking force, than a primary. The reason for this is to reduce unintended free flows. This is not always the case and regardless the second stage cracking effort can be adjusted to primary second stage values.

 

[lowwall]

Typically an octopus is set up slightly stiffer, higher cracking force, than a primary. The reason for this is to reduce unintended free flows. This is not always the case and regardless the second stage cracking effort can be adjusted to primary second stage values.

I was debating whether to include this caveat.

It is correct that Mares specs the cracking pressure range from .1 to .3 inches of water greater for second stages delivered as octos depending on the specific model.

This is going to be noticeable for most of their classic downstream (unbalanced) second stages. It can be adjusted out, but it is a little fiddly.

However, it's less of an issue for their newer balanced adjustable second stages. For the Ultra ADJ the acceptable cracking effort range for the primary is 1.1 to 1.3 inches of H2O and for the octo it is 1.2 to 1.4 inches. Since the ranges overlap, it's possible that there may not be any difference between any given octo and primary. Even if it is there and noticeable, you can probably use the adjustment knob to dial it out. At worst you'll need to adjust a part cleverly called the adjusting screw that is easily accessible by removing the adjustment knob.

 

[DiverDave65]

OK Thanks everyone for your responses!!!

 

[Scared Silly]

A slight tangent, when I was playing DM I wold advise divers to descend with their oct. If it was not breathing worth a damn they might want to consider fixing it or getting on that breaths decently. Cause when Davey Jones comes a calling yah want to be able breath.

For the OP I tune all of my second stages the same. As such, they are the same all the way around.