CO2 regulator pressure behaviour

jonny_ftm

Guru Class Expert
Mar 5, 2009
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Hi,

I have a Dennerle CO2 regulator with double manometers.

Each time I open my needle valve, the service pressure drops. If I close the needle valve, the working pressure increases. Thus, adjusting bubble count is very hard since working pressure variations significantely affect the bubble count (the higher the working pressure, the faster is the bubblle count). So, to increase my bubble count, I need each time to open the needle valve and than readjust the working pressure.

Is my regulator behaviour normal or is it a bad manufactured product. I thought working pressure should be fixed with its own dedicated valve and not being affected by distal pressure variations

Many thanks to clear this for me
 

Tom Barr

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Jan 23, 2005
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Most in the USA tend to use a few cheap brands, or we get a really nice welding supply CO2 regulator.

Even with some of the cheaper brands, I've not seen much drop.

By adjusting the outlet pressure, typically in the 15psi range(I rarely use the metric equilvalent), this should be ample pressure that should remain stable. some brands have only a pre set out let pressure, others such as dual gauge give you gas tank pressure(800-1000psi), and outlet pressure(adjustable, 0-60psi or so, with most using 10-20psi ranges).

Yes, if the outlet pressure was too low, it would make adjustments very hard!
Might be defective?

I have not used the brand as it's rare in the USA, more a European brand.
I like Victor Regulators for CO2, they have been running for 20 years without any issues.

If you set the outlet pressure at say 2-4psi, then you'd have the issues you sound like you are having. If you set the outlet pressure at say 15-20psi, there should be no affect on adjusting the bubble rate, even at very high CO2 flow rates or bubble/second.

Regards,
Tom Barr
 

jonny_ftm

Guru Class Expert
Mar 5, 2009
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Thanks Tom for the feedback

I'm getting concerned now. I have to set my working pressure to 2 bars (30 Psi) to get any CO2 flow. I also noted that my Solenoid has its green LED dead, but it still works. Yet, even a slight move on the needle valve will result in a significant variation of the working pressure.

Does it mean a damaged regulator? Bad news in that case as they are rather expensive in Europe
 

jonny_ftm

Guru Class Expert
Mar 5, 2009
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Feedback and conclusions:

I changed my canister today from a 2Kg to a 7.5Kg CO2.

I installed a new Tunze 7077/2 regulator: no more problems with the working pressure changing when I turn the needle valve. Also, made a leak test by turning off the canister main valve and shutting down solenoid. I saw that pressure rapidely drops with my Dennerle Regulator despite no leak on all circuit identified. I finally figured out that it was leaking from the needle valve screw :confused: The more I open the needle valve, the more it was leaking. With the Tunze regulator, no problem. My Regulator was bad cheap quality despite the price. It is the last time I buy sometjing from an Aquarium Specific brand. Better go with technical/industrial cheaper/better quality equippement



I also decided to stop the hassle with those end of life canister pressure rebounds.
A simpel test to see if the regulator can handle a stable working pressure at the end of life of canister is as follow:

Shut off main canister valve. Keep solenoid and all other valves open as in your setup. Canister pressure will rapidely drop and you can monitor the working pressure on the regulator gauge. If it increases before dropping, it means the regulator won't handle end of life of canister --> CO2 increase that can be dangerous to your fish

Sadely, even the Tunze didn't pass that test, despite being followed by the unique 51-1-12 Ideal needle valve

I made much research and finally found that you will need a 2-stage regulator to have a constant working pressure even when canister pressure is dropping. I also found this one:

pressure regulators

Simple stage regulators with a pressure compensation claiming for 2-stage regulator performance while keeping with a less than 50 USD price. They also have 2-stage regulators, all available in Germany for Europe: gasetechnik24.de - Ihr Partner für Druckminderer und zentrale Gaseversorgung


I'll give them a try soon, and will add a 51-1-12 valve to them
 

Tom Barr

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My kingdom for a nice CO2 solution:eek:

A good regulator is well worth the effort, same for a needle valve and solenoid.

From there, we can move downstream to a good bubble counter, check valve and then finally to CO2 diffusion.

Each point is critical.

Once in the water, CO2 needs measured somehow or careful eyeballing(fish, plants, algae etc). Riccia seems to do well attached to stones.

Pearls well 1/2 way through the day when CO2 is good. If not, not enough CO2.

If plants are happy, no algae, fish fine, then do not add more.

We can easily mitigate CO2 stress several ways and have much more effective management:

1. Good flow, not enough to break the water's surface but a little less that that is a good rule of green thumb.
2. Good quality CO2 equipment and Gas tanks, needle valve.
3. Effective measurement(harder)- relative measurement once you know what to look for.
4. Less light= less CO2 demand from plants
5. Good filter, routine cleaning, water changes often=> less organic decomposition and O2 draw
6. Reasonable long term fish load(not overstocking)
7. Smaller fish= less O2 than larger say Discus etc requirements(the answer why is obvious, think about it- do not answer PKM! Let them think about it))
8. Good dosing, good feeding of fish
9. Riccia rock, about 1/2 way through the day, the riccia stone will start to pearl well(biotest). This suggest good CO2.
10. Watch the tank, respect CO2, adjust methodically and carefully.

Not quite as simple as it seems.
Sadly, many give it a passing fancy at best.
Guess they know it all with respect to CO2?
Must be nice.


Regards,
Tom Barr
 

jonny_ftm

Guru Class Expert
Mar 5, 2009
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Many thanks Tom for that sum-it up

Actually, thanks to the advices I received here, I moved to low light, and it made a big difference. I have no algae except stable BBA on only one wood that I don't touch as it is self limited and adds some nice look to my wood.

Arriving at the end of the canister made my life a nightmare for 3 weeks with a 2Kg canister (CO2 spikes because of working pressure increases when canister pressure drops). Now, I moved to an industrial 7.5Kg canister that will last me a while. If I kept my actual regulator, I'll have to deal with 2 months of pressure fluctuations when the canister will run out

So, investing in a good regulator, needle valve and swagelok adapters is definite +

Also, I posted the ways to test the regulator for "end of life of canister behavior" and to look for leaks with the pressure drop test when solenoid is off and canister shut-off, as they could help people decide
 

nipat

Guru Class Expert
May 23, 2009
665
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jonny_ftm;41045 said:
Feedback and conclusions:

I changed my canister today from a 2Kg to a 7.5Kg CO2.

I installed a new Tunze 7077/2 regulator: no more problems with the working pressure changing when I turn the needle valve. Also, made a leak test by turning off the canister main valve and shutting down solenoid. I saw that pressure rapidely drops with my Dennerle Regulator despite no leak on all circuit identified. I finally figured out that it was leaking from the needle valve screw :confused: The more I open the needle valve, the more it was leaking. With the Tunze regulator, no problem. My Regulator was bad cheap quality despite the price. It is the last time I buy sometjing from an Aquarium Specific brand. Better go with technical/industrial cheaper/better quality equippement



I also decided to stop the hassle with those end of life canister pressure rebounds.
A simpel test to see if the regulator can handle a stable working pressure at the end of life of canister is as follow:

Shut off main canister valve. Keep solenoid and all other valves open as in your setup. Canister pressure will rapidely drop and you can monitor the working pressure on the regulator gauge. If it increases before dropping, it means the regulator won't handle end of life of canister --> CO2 increase that can be dangerous to your fish


Sadely, even the Tunze didn't pass that test, despite being followed by the unique 51-1-12 Ideal needle valve

I made much research and finally found that you will need a 2-stage regulator to have a constant working pressure even when canister pressure is dropping. I also found this one:

pressure regulators

Simple stage regulators with a pressure compensation claiming for 2-stage regulator performance while keeping with a less than 50 USD price. They also have 2-stage regulators, all available in Germany for Europe: gasetechnik24.de - Ihr Partner für Druckminderer und zentrale Gaseversorgung


I'll give them a try soon, and will add a 51-1-12 valve to them

My Azoo didn't pass the test too. I had checked for a used 2-stage Victor
but the shipping cost killed the deal ($56.95), quite heavy.

Only if there was something like an accessory to add the lacked function
of a single-stage regulator... :(
 

Tom Barr

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Jan 23, 2005
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Yes, there is way around the single stage reg's, tell folks not to buy them and hopefully the aquarium companies wills top selling cheapo reg's

Regards,
Tom Barr
 

sumolang

Junior Poster
Jul 8, 2009
2
0
1
Hi everyone

i missed a very nice conversation and i'm facing a problem with my co2 rate.
i am using a cheap regulator made in china, in my 55g tank the bubble was unstable i had to check it for every couple of hours:(

when i moved the regulator to my 25g tank the bubble rate is now stable.
i bought a better regulator later on, and when i used it on my 55g tank it happenned again, the bubble became unstable.

please help :confused:

is it related to pressure balance between my diffuser and my bubble counter??
 

jonny_ftm

Guru Class Expert
Mar 5, 2009
821
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Suerely you got two chipo regs. Most regs that are sold by aquatic companies and those chipo china/taiwan regs, are indeed cheap quality too. A good single stage, will have a very stable working pressure, despite the changes of pressure downhill the reg (needle valve openeing/closing, diffuser...). A bad reg, won't keep a stable working pressure for even changes in downhill pressure (any movement of the needle valve, change in flow of filter for external CO2 reactors...). Furthermore, most of these reg have a very bad needle valve that won't keep a stable bubble rate at high CO2 flow. It could even leak when needle valve is opened, like my Dennerle "reputed German quality" reg that can't keep a stable working pressure

I can tell you for sure that the Tunze 7077/2 have a very stable working pressure, but it is single stage and will have the dump effect at the end of life of canister. The needle valve is of good value, nothing compared to an ideal valve but surely enough for most people if you tweak it a bit. At least, it has a stable flow. It costs half a double stage reg too...
 

dutchy

Plant Guru Team
Lifetime Member
Jul 6, 2009
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Why not buy a Ph controller? Bubble rate gets kind of unimportant when set higher than a minimum to reach the needed CO2 level. End of tank problems are automatically controlled too.

I know an electronic contoller can fail, but what's the chance? I think there's more chance to kill fish without one.

Regards,
dutchy
 

jonny_ftm

Guru Class Expert
Mar 5, 2009
821
2
16
Feedback: they ask for 48 euro shipping to a neighbourhood country, same price as their reg :mad:
They refuse to switch to another shipper


No interest is left at this price for their product, I opted for a real 2 stage reg. The thing is really heavy but still enough slim to easily fit behind an aquarium
 

GillesF

Member
Nov 1, 2010
404
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Antwerp, Belgium
jonny_ftm;42511 said:
Feedback: they ask for 48 euro shipping to a neighbourhood country, same price as their reg :mad:
They refuse to switch to another shipper


No interest is left at this price for their product, I opted for a real 2 stage reg. The thing is really heavy but still enough slim to easily fit behind an aquarium

I'm sorry to bump this old thread but I'm also looking for a dual stage (I'm from Belgium). I've found a company that can deliver the "Vulkan F10" at a reasonable price (10€ extra) but will it work?

@Jonny_ftm: where did you get your 2 stage regulator?
 

barbarossa4122

Guru Class Expert
Dec 29, 2009
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NYC
Tom Barr;41069 said:
My kingdom for a nice CO2 solution:eek:
9. Riccia rock, about 1/2 way through the day, the riccia stone will start to pearl well(biotest). This suggest good CO2.

Hi Tom and all,

What is a Riccia rock and where can I buy it ? Thanks.
 

barbarossa4122

Guru Class Expert
Dec 29, 2009
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GillesF;60124 said:
I'm sorry to bump this old thread but I'm also looking for a dual stage (I'm from Belgium). I've found a company that can deliver the "Vulkan F10" at a reasonable price (10€ extra) but will it work?

@Jonny_ftm: where did you get your 2 stage regulator?

Hi Gilles,

I might have a Concoa 212 (0-30 psi) in a couple of weeks. I am using it right now but, I bought a new regulator, an AIR PRODUCTS E12-244B350 and my Victor 453b is been fixed right now. I really want to keep the Concoa as a spare but, I'll send/sell it to you if you want.
Darn, I just checked with the USPS international medium flat rate box is $45.00 for shipping to Belgium.
 
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Tug

Lifetime Charter Member
Lifetime Member
Jan 5, 2009
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Riccia fluitans attached to a rock.

What is a Riccia rock and where can I buy it?
You already have what looks like one to me. Well, you have a Riccia bridge. Same thing.
 

barbarossa4122

Guru Class Expert
Dec 29, 2009
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Hi Tug,

I see. I thought it's some special rock called Riccia. How do you like the bridge Tug ? Depending on your answer, I'll show your post to my wife:)