Which second stages to use.

[a4lod]

My tanks have been fitted with h-valves as I only dive with single tanks. For my first stages I have two SP Mk20's. For my second stages, I have a G500 & a G250. I also have a R190 - which sits at home. After reading my DIR Fundamental's book I read that one of my second stages should be a high performance balanced (I believe this was the term) second stage and the other should be a high performance unbalanced second stage (again I believe this was the term used). If this is true, should I substitute one of my 'G' second stages for the R-190? If so, which one? Please respond. Thanks.

[Campana]

both your second stages are balanced high performance. I believe the idea of using a non balanced second stage as your backup has to do with having a simple, reliable, detuned back up that won't free flow.

However, my opinion is that if you are happy with your second stages the way they are, why would you substitute the 190? I would leave them alone.

The G250 is my favorite regulator. I don't mind the size, and it tunes up very nice. Especially nice are the older ones with the metal tube inside instead of the more modern plastic tube.

If you have problems with free flow on your back up regulator, just turn the knob down a bit.

[buff]

The 190 is a very good regulator. I'd keep it.

[ucfdiver]

I only have g250's and g250v's. I don't see the point owning a low performance regulator

[Wayne at DiveSeekers]

I like having 2 adjustable second stages so I would use the G250 as my primary and use the G500 as backup. Keep the G500 knob all the way back towards you where it is hardest to breathe and less susceptible to free flowing. Adjust the knob to your liking when you switch to it. Keep the R-190 incase you ever need it.

[PfcAJ]

Yes, use the unbalanced r190 as a backup. G250s are way more finicky than 190s.

[Lobzilla]

Yes, use the unbalanced r190 as a backup. G250s are way more finicky than 190s.

Would you care to elaborate?

[PfcAJ]

Sure. I own around 12 g250/v/hps. They require significantly more maintenance than my r190/r395s that I use as backup regs.

For a backup, I prefer a simple, highly reliable reg that will work every single time and not give me any hassles at all.

[ucfdiver]

Sure. I own around 12 g250/v/hps. They require significantly more maintenance than my r190/r395s that I use as backup regs.

For a backup, I prefer a simple, highly reliable reg that will work every single time and not give me any hassles at all.
Has a g250 ever failed closed on you? I didn't think that was physically possible...

[PfcAJ]

No, of course not, but I don't want my backup to fail open, either. I just want it to work, not freeflow, be easy to clear, and otherwise rock solid. It doesn't need to breath like a dream.

Backup reg needs to be like backup lights. Simple and reliable.

[Lobzilla]

My impression is that a G250(V) with the cracking pressure screw all the way in and the VIVA in surface position is way more free flow resistant than a R190 adjusted to specs. There is no difference in clearing them. IMO the only reason to prefer a R190 would be cost (purchase and maintenance) and I like to separate financial concerns from risk assessment. Even as I have a serviced R190 sitting in a drawer I cannot convince myself that it should replace the G250 currently on my necklace.

Please convince me otherwise. This would save me from having to buy another G250(V) for stage or deco bottles. (The prices of used G250s have gone crazy).

Edit: Maybe my R190 should go on the O2 bottle and the G250 stay on the necklace. What do you think?

[awap]

Sure. I own around 12 g250/v/hps. They require significantly more maintenance than my r190/r395s that I use as backup regs.

For a backup, I prefer a simple, highly reliable reg that will work every single time and not give me any hassles at all.

I am having a hard time making good sense of this. Sure, there are a few more o-rings, including the dynamic o-rings in the balance chamber, in a G250 than in an R190; but all o-rings are quite reliable and require little maintenance if properly installed. Just what maintenance are your 250s requiring that your 190 does not? Both have mfgr recommended annual service but both can usually go for many year of satisfactory, reliable performance before that "annual" service is really required. The lighter spring tension on the G250 should reduce seat engraving but if your 2nds are stored with that spring tension relieved, seat engraving can be almost totally avoided. So what exactly seems to be the problem?