# 2-Stage vs. Single Stage Regulators



## davemonkey (Mar 29, 2008)

...not to be confused with 2-gauges and single gauge. For the sake of argument, let's assume every aquarium regulator in consideration has 2 gauges. One is the tank pressure (high pressure gauge) and the other is the working pressure (low pressure gauge). So, now let's talk "stages".

I know there has been discussion on this before. But now I can actually put experience behind my opinions on this. 

The last regulator I had was a single stage, Azoo. At that time, I got a decent deal on it at $65 brand new (it came with a solenoid and needle valve). I wasn't thrilled about the low pressure being pre-set and non adjustable, but it worked well enough. The only bad thing was that toward the end of my CO2 tank's "breath", I'd get that end-of-tank-dump (somewhere around 200-250 psi).

Fast forward to now, and I've got a 2-stage AirCo. The sticker on a brand new one of these is WAY out of my budget at around $400-500. However, you can regularly find these on ebay used for $25-60 give or take. I paid $39 form mine, plus a few bucks for shipping. It was previously used commercially and was replaced by a newer model, but these things are commercial grade and are reliable. It did not come with a solenoid or needle valve, but I EASILY got twice the regulator that I had for less $$. Plus, I got to pick out a good needle valve to go with it (though I could have used the old one from the Azoo had I chosen). Just yesterday I checked my tank as it was nearing empty. The tank pressure was at 150 psi or less and I was still counting the same bubbles I had when the tank was full. No end-of-tank-dump, more regulator for less $$...I rest my case.

...or do I? The needle valve I had was either a clippard or some copy-cat brand. The one I have now is an Ideal. Perhaps that also has a role to play here (as far as not dumping CO2).

I'd like to hear your thoughts/opinions/experiences on this...


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## AquaBarren (Nov 6, 2009)

I have an ideal needle valve on a single-stage setup from Sumo. Run every tank to empty, have never had an eotd. 

Quality needle-valve definitely helps. Dual-stage better. 

DIY 2-stage regulator projects are worthwhile and fun DIY projects that net better for less. Anyone looking at pressurized should consider it.


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## davemonkey (Mar 29, 2008)

Okay, that's good to know that you have great control with a better needle-valve as well, even on a single stage.

Yeah, putting together the fittings etc... on the 2-stage was alot of fun and was MUCH easier than I thought.


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## Jark (Feb 6, 2010)

I was able to pick up a never been used 2stage for $10 and a swagelok S meter valve for 20 on ebay. Then after picking up the solenoid and check valves from Clipard and some adapters from Swagelok I was still saving money if I, if ignored the shipping cost from each place. If I add in all the shipping/handling I am not saving anything. By the end though it should be a beefy system. I is fun building them. The thing looks insane and the 2 stage is so big I have to secure the tank otherwise it tips over.


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## inkslinger (Jan 1, 2005)

I've always had a m3 Regulator Econo - Dual Gauge single-stage setup for 10yrs with a
Swagelok B-2MA2 needle valve an Burkert's 6011 Solenoid Valve , I never experience a EOTD.
At one time I use a Clippard Needle Valve with a co2 controller. Now I just run it on a timer with lights.
Pic shows my old Clippard Solenoid Valve an my old Clippard Needle valve witch were replace.


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## davemonkey (Mar 29, 2008)

For those not sure what the difference is between a single-stage and two-stage, here's a pic of a two-stage (the 2nd "stage" is the pressure step at the rear of the regulator...it's not flat on the back like a single-stage is).


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## neilshieh (Jun 24, 2010)

i personally like the huge hulking beasts, namely VTS 450D and the matheson 8-###'s although the smaller VTS 250 series work just fine and won't really tip your co2 cylinder. the single stage regulators are the size of that "hump" on the back of DSR's which i thought was pretty funny. I've tried a single stage regulator before but i didn't like it, simply because if you're going to be dealing with a gas like co2 running into your tank, might as well be very safe and use a dual stage regulator, with a single stage you have to worry about the end of the tank dump and what not, but a used dual stage is cheap and more practical than a very expensive ideal needle valve. for post bodies i use STC solenoids and needle valves which are cheap but good. combined with a DSR you've got a good regulator setup for under 50 dollars.


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## farrenator (Dec 21, 2008)

With that VTS $%)D, you converted the pipe/nipple to use CO2? I have gotten conflicting info from Victor regarding converting these 450D to use with CO2. One tech told me the seat material in the regulator would be fine to use with CO2 and another told me that it wouldn't. What is your experience? It seems like it would simple enough to just swap out the pipe/nipple to a CGA 320 and be done with it.



neilshieh said:


> i personally like the huge hulking beasts, namely VTS 450D and the matheson 8-###'s although the smaller VTS 250 series work just fine and won't really tip your co2 cylinder. the single stage regulators are the size of that "hump" on the back of DSR's which i thought was pretty funny. I've tried a single stage regulator before but i didn't like it, simply because if you're going to be dealing with a gas like co2 running into your tank, might as well be very safe and use a dual stage regulator, with a single stage you have to worry about the end of the tank dump and what not, but a used dual stage is cheap and more practical than a very expensive ideal needle valve. for post bodies i use STC solenoids and needle valves which are cheap but good. combined with a DSR you've got a good regulator setup for under 50 dollars.


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## Left C (Jun 14, 2005)

Jark said:


> I was able to pick up a never been used 2stage for $10 and a swagelok S meter valve for 20 on ebay.


That's an excellent deal! That's the way it was a few years ago.



Jark said:


> Then after picking up the solenoid and check valves from Clippard and some adapters from Swagelok I was still saving money if I, if ignored the shipping cost from each place. If I add in all the shipping/handling I am not saving anything. By the end though it should be a beefy system. It is fun building them. The thing looks insane and the 2 stage is so big I have to secure the tank otherwise it tips over.


This is a head's up. Keep an eye on your Clippard solenoid for leaks. There were quite a few instances of this happening not so long ago.

If it fails, a Burkert 6011 solenoid with Buna-N seals from freshwatersystems.com may be an option. You will need one of the two LED cable plugs plus an 18/3 power cord (the more common 16/3 power cord can be used with a bit of fiddling). An 18/3 power cord is used on many computers plus some electrical suppliers and Americord.com carries them. This is one of many that Americord carries.

6011 brass solenoid: http://www.freshwatersystems.com/p-6016-22-miniature-solenoid-valve-brass-body.aspx
6011 stainless steel solenoid: http://www.freshwatersystems.com/p-6015-22-miniature-solenoid-valve-stainless-steel-body.aspx
Led cable plug w/no circuitry: http://www.freshwatersystems.com/p-6017-cable-plug-to-din-43650-led-no-varistor.aspx
Led cable plug w/varistor: http://www.freshwatersystems.com/p-6018-cable-plug-to-din-43650-led-with-varistor.aspx


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## Jark (Feb 6, 2010)

I think I got lucky on Ebay for sure. I happened to find a few new sellers that had auctions up. Everything with a buy it now price was expensive. 

Thanks for the heads up on the Clippard valves. I did notice that it doesn't cut off 100% of the flow. I just seems to stop most of the flow. That is with nothing else down steam to provide resistance. After popping on the check valves and bubble counter the flow stops completely with solenoid. Thanks for the links. I think I ran across another post by you advising others to use the Burkert valves. It was after I had already ordered the Clippard parts though. From the other posts I looked at again today it looks like I will need the Burkert part within the year if other peoples experiences are foretelling my future.


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## Left C (Jun 14, 2005)

The Burkert solenoids at freshwatersystems.com are the new models with the Buna-N seals and LED cable plugs. AquariumPlants.com sells the solenoid with Viton seals and non-LED. Buna-N works better for CO2 duty, but Viton is a good "all around" seal material that will work with a wide variety of media.


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## bsmith (Dec 13, 2006)

The needle valve has nothing to do with controlling EOTD. All the NV does is control flow based on a specific input pressure. The DSR is the reason you can run your tank dry with no issue not the Ideal NV. 

Aquabaron you are just lucky and im certain you have had EOTD but it was never bad enough to kill any of your fish. A SSR cannot hold a constant output when the bottle pressure starts to drop, it was not designed to do that.


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## bubbleboy (Jul 18, 2011)

Single stage regs work just as good as dual stage as long as you have good head pressure coming from the tank. The OP was correct, single stage regs will flare when the tank pressure gets low and bsmith is correct is saying a needle valve only controls the flow for a fixed pressure.

As long as you do not run the tank low when you use a SSR you will not have any issues and single stage victors are awesome for those on a budget. One concern with used regs though, especially those that have been run with oxy for years, the stainless diaphragms and other parts do corrode because oxygen is a oxidizer and even the best grades of stainless will rust (if any supply tank has had any moisture in it). I think monel is the only type of stainless that does not rust because it is like 75% nickel and 25% copper, Zero iron in the mix. 

When I build setups I will most often have the regs referbed so they are "as new" or buy factory referbed. That does not mean all used regs are bad.. but some are wore out and you will notice the LP side drift when the outflow is off. (preassure will slowly build on the LP gauge)


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## lipadj46 (Apr 3, 2011)

the cool thing about the industrial type regulators is that they can be bought cheap "as is" and rebuilt for $60 or so and pretty much last forever.


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## Left C (Jun 14, 2005)

A few years ago, I remember taking one of my Azoo regulators over to my local Victor dealer where I get my CO2 tanks swapped out to show it to him. When he saw it, he started laughing. He said to his buddy: "Look at that cute, little regulator. That little thing has a heater on it" and he cackled. I told him that it was a solenoid and how it worked with the needle valve. He was still laughing at it. The next time that he saw me, I had a mint condition VTS253A-1993. I told him that I got it on ebay for $29.30 shipped. His eyes got big. Then, I asked him what the other stage did and he told me how two stage regulators operate. I was hooked ... hook, line and sinker!


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