No Octo while diving with redundant air supply

[Norwegian Cave Diver]

Sure glad you're not your my diving instructor.

I configure my gear however the hell I want to.

And it's not your way.

Read why it should be in the front and then give reasons why in the back is better?

 

[KenE]

Read why it should be in the front and then give reasons why in the back is better?

Really doesn't matter, OP says he is back mounted. Question is about whether a third second stage is needed, can we please stay on topic.

My answer to OP: it depends on if you want access to the remaining gas in your primary cylinder upon primary second stage failure. If not, no, if so, then yes.

 

[Norwegian Cave Diver]

Really doesn't matter, OP says he is back mounted. Question is about whether a third second stage is needed, can we please stay on topic.

My answer to OP: it depends on if you want access to the remaining gas in your primary cylinder upon primary second stage failure. If not, no, if so, then yes.

I am on topic.
When on back mount single tank - and you want a second independent source of gas - where should that gas be? Front or back? Front stage/pony is far more versatile.

 

[JoeTPhilly]

I think a back mounted pony is a bad idea due to the possibility of confusion on which tank you are breathing. If back mounted, I think the octo should be removed to cut down on the confusion. Bungee necklace the back mounted pony and if you have to switch to it the dive is over. Be safe.

 

[Gandalf-the-Diver]

I usually dive solo, but on my LDS drop in dives. As one of the "regulars" in the group, sometimes I see if the DM needs help with new divers. If not, I swim along, with the group. If anyone in the group has trouble, I have an octo they can access. I see more problems with constantly taking off or putting on, the octo to my sage 1.

 

[Norwegian Cave Diver]

Sure glad you're not your my diving instructor.

I configure my gear however the hell I want to.

And it's not your way.

Where is the best place for a stage/pony?
In the front makes it more versatile. You could donate the stage - breathe from it for part of your dive and save more back gas or not breath from it and it there for back up only.

 

[JoeTPhilly]

I usually dive solo, but on my LDS drop in dives. As one of the "regulars" in the group, sometimes I see if the DM needs help with new divers. If not, I swim along, with the group. If anyone in the group has trouble, I have an octo they can access. I see more problems with constantly taking off or putting on, the octo to my sage 1.

I think you just made the argument for a slung pony.

 

[Pressurehead]

I see more problems with constantly taking off or putting on, the octo to my sage 1.

Mine stays on, solo or not.
To answer the OPs question.

 

[KenE]

I am on topic.
When on back mount single tank - and you want a second independent source of gas - where should that gas be? Front or back? Front stage/pony is far more versatile.

Again, you are missing the OP's original equipment description, he says "diving with a completely redundant system on my back". So, he has already said his redundant source is back mounted, so you are off topic trying to say slung is better. I am not arguing your point, but rather stating the question is about number of second stages and not location of redundant source.

 

[Norwegian Cave Diver]

Again, you are missing the OP's original equipment description, he says "diving with a completely redundant system on my back". So, he has already said his redundant source is back mounted, so you are off topic trying to say slung is better. I am not arguing your point, but rather stating the question is about number of second stages and not location of redundant source.

I understand and Im saying it would be much better in the front.