Poseidon xstream mk3

[jlovold]

I had a dst, but it was almost always leaking a tiny bit through the turret joint.

never had any issues with the mk25s though. They have not been served for in two and three years, but still working perfectly.

 

[Bison Ravi]

Thanks guys, for all the information. I'll probably end up buying a set to try them. It's not that my atomics don't work, but if I can find regulators I like more, why not?

If I do buy them I'll be sure to write my impressions here.

Cheers!

 

[jlovold]

If you can test a set first, I would do that, as the way they deliver air is a bit "special".

The cracking-pressure is a bit high, but when it starts delivering, you will feel a bit like a hamster...

 

[ev780]

proprietary hose concern is gone, even on your jetstreams. If you have the 3960 first stages with the OPV in the bottom, https://www.divegearexpress.com/regulators/adapters/hose.shtml $13/second stage and you're back to normal hoses.

the first stages are actually smaller and lighter than most, the new MK3 design is a brilliant little first stage, vastly superior to any other design I've seen. Wish they would put out something with their internals that had a swivel turret with 5th port, but that's a want not a need.

Yeah my firsts are the older ones.

 

[tbone1004]

ahh, even still, you can get an OPV for the first stage for like $3, so it pays for itself real fast when you have to replace that first hose. Also is nice if you want to swap just the second stages over to a different set of first stages, you don't have to pull the hoses around.

Adapters for the Cyklons as well, and rumour has it, they are making a modification to the MK3 first stage so they can run up to the 185psi IP required for the granddaddy of all second stages....

 

[ev780]

Good to know. Thanks.

 

[Blue Quaker]

We have 4 Xstreams which we use on our back gas and 4 "Cyclon" Xtreams that we use on our stage regs. The Ip setting has not been a problem for the Mk 3 1ST stages with the Cyclon 2nds...We run them @ 165psig IP, with no problems with IP creep or 2nd stage performance. The Xtreams have been superb breathers at all depths and temperatures tht we have used them in.

 

[tbone1004]

165 is fine for deco and stages, but for backgas they really should be up in the 180-185psi range which apparently causes problems on the mk3's, I'd still love to get my hands on a set though.

 

[Blue Quaker]

The old US spec. on a Cyclon 300 was 174-181 psig @ 300 psig supply, which because the Ist stage was unbalanced, gave a 145ish IP @ 3000 psig supply. I ran with Cyclon 5000s for many years at around 165 psig IP near the max European conversion from the BAR setting. I got the 165 psig IP recommendation from Poseidon, as The Canadian Distributor knew why I was buying the combo of 1st and second stages, and he checked with Poseidon HQ before sending them out, as my combo wasn't one of the official regulator first/2nd stage combos offered by Poseidon. AFAIK there has never been a recommendation to go over 181 no matter which 1st Stage the Cyclon 2nd stage was attached to.

 

[tbone1004]

good to know, I know the old first stages had horrid balancing mechanisms in them, but just checked my manual and it still says 181 for the new first stages. I had heard from Poseidon they were making some mods to the MK3 to make it happier at that high of an IP for the whole duration, but good to know about the 165psi being acceptable.