Mix & match 1st & 2nd stage?

[runsongas]

pretty much any will work from the balanced ones (eg 2xxx/3xxx series and the mk3), but you would want either the matching mk3 first or the older 3xxx style they still sell with the cyklon as those both have an integrated opv if you intend to use 2 upstream 2nds (xstream/jetstream) and don't want to use an OPV off the LP port or get the expensive poseidon hose with an integrated opv. the cyklon 300 1st stage is unbalanced, but is not that common anymore.

 

[scv]

pretty much any will work from the balanced ones (eg 2xxx/3xxx series and the mk3), but you would want either the matching mk3 first or the older 3xxx style they still sell with the cyklon as those both have an integrated opv if you intend to use 2 upstream 2nds (xstream/jetstream) and don't want to use an OPV off the LP port or get the expensive poseidon hose with an integrated opv. the cyklon 300 1st stage is unbalanced, but is not that common anymore.

I've found a 'used' Poseidon Jetstream model 1225 first stage, this is adequate for the XStream?

 

[scv]

I've found a 'used' Poseidon Jetstream model 1225 first stage, this is adequate for the XStream?

Correction, I think 1225 is the yoke adapter. The first stage is stamped 2950, and is like new. Also found a 3790

 

[scv]

Id also like to add that I will be using NITROX with this system.

 

[2stroketony]

More of a pain to mix and match those regs. Best to go all Poseidon which are top of the line regs. Hollis 500se is also a top of the line high performance reg.

 

[lowwall]

Correction, I think 1225 is the yoke adapter. The first stage is stamped 2950, and is like new. Also found a 3790

Poseidon regs were sold as a first and second bundle. The number stamped on the first stage is the code for the bundle.

2950 is the code for the Poseidon Cyklon 5000 (Diveair outside the US). It uses the 3257 first stage. This does not have a built in OPV and would need to be retuned for an Xstream second. If the one you are looking at only has 3 LP ports, you would need to use the OPV on the hose end.

The 3790 does have the built-in OPV valve.

 

[lowwall]

Do you have a good Poseidon tech in your area? These are not the most popular regs in the US and they have some quirks which might not be dealt with correctly by a tech without specific training.

I also suggest you read this older thread which covers a ton of info including the breathing characteristics of Poseidon regs before jumping in: Questions about Poseidon regs.

 

[scv]

Thank you all for the detailed information. I decided to put the Poseidon on the back burner and just picked up an Aqualung Legend. Reviews on this reg setup sold me. In the future ill consider picking up the Poseidon as a complete package.