Simple Question

[GLENFWB]

Is there any problem with switching a first and second stage around? For example, if I have a Sherwood first stage and want to put a Scubapro second stage on it. Are they somehow balanced together? Are there any potential dangers in doing this?

 

[Nick_W]

Nope. Some manufacturers may tell you that you should only use their brand of second stage with their brand of first stage, but there's nothing wrong with mixing and matching a bit.

 

[Thalassamania]

You need to do a little checking. For example, at the extremes, an Aquadyne second stage wahts to see 60 psi over ambient whilst a Cyclon 300 wants 190 ... they will no function together. Most popular regs have an IP of 130 to 150 PSI and it's a good idea to try and match the IP specification for both. If you can't the IP on the first stage can usually be set to that required by the second stage.

 

[Papa_Bear]

I have an xs SCUBA first stage and a US Dives Micro Lite as a second and a Duo-Air Secondary! Feel free to mix and match!

 

[Thalassamania]

I have an xs SCUBA first stage and a US Dives Micro Lite as a second and a Duo-Air Secondary! Feel free to mix and match!

Tell me, would you dive a Sherwood second stage on a Poseidon first stage?

 

[Papa_Bear]

Don't know the models and I would check the specs on pressures to see if it were a good match? Given Poseidon, it maybe too proprietary as a first stage, but a little checking will ferret the answer out! I will get back to you on that match!

 

[Thalassamania]

Try looking up to post 3. Then consider what you are about to tell new divers before you start typing ... please!

 

[plumbcrazy]

It may turn out fine and then again..... I don't think I would look for the answers here, giving the fact you really don't want to be without them at 60 feet or more. Your local service center should be able to set them as they need to be, that is if they will work together.

 

[Damselfish]

post 3 covers the matching thing. Another thing to consider is that it can be a little inconvenient to service if you don't have a shop that happens to do both brands.

 

[DA Aquamaster]

Matching pressures just by brand does not really work as most companies use an acceptable IP range of 120-145 psi. So...if you get a second stage tuned for an IP of 120 psi and put it on a first stage with an IP toward the upper end of the range, you will get a freeflow.

This also creates a potential problem within the same brand as the same thing can also occur.

For that reason second stages sold as octos are set with a higher inhalation effort that also makes them compatible with a first stage operating at or even over the normal 145 psi upper end of the IP range - the downside is that they also in effect breathe like rocks, something that is not neccesary on an octo, especially if it adjustable or has an adjustable flow vane for freeflow reduction or prevention.

So the best bet is to ask (and expect it for free since you bought it from them) the shop to tune your octo to your first stage to optimize its performance.

The other mix and match issue is that you want to be sure that you can get both brands serviced. Some shops will not service brands they are not dealers for and in some cases they cannot even get parts for brands they do not sell. Your dealer may sell both brand "A" and brand "B" this year, but next year if they drop brand "A" to pick up brand "C" you can get stuck - as after a few years brand "A" will stop sending them parts for servicing your reg (or part of a reg)even under warranty as they will expect you to take to to another brand "A" dealer in the areas. Of course this new brand "A" dealer will almost by definition not be a brand "B" dealer since your old dealer still has that brand, so your annual service logistics for your mixed and matched Brand "A" and "B" reg just got really complicated.

In short, mixing and matching works just fine as long as your dealer is committed to both brands and stays with them for the life of your reg, but if you move or your dealer changes the lines he carries it gets problematic in a hurry so with regard to long term planning it is something I recommend people avoid.