Why is my Rhinox CO2 tubing leaking?

Fishproblem

Member
I've just set up my first pressurized CO2 system, and am feeling pretty discouraged. The regulator, an FZone Triple stage regulator with solenoid, is working perfectly. However, I have leaks at the connection points on either end of my check valve and at the connection point on my diffuser.

I'm using the Rhinox CO2 Saver tubing, the DGZZI One Way non return check valve [link here] and the Jardli U shape CO2 diffuser. (It looks like the DGZZI valve is identical to the Yagote version).

Are these somehow incompatible? I first just put the tubing on without following the instructions to boil the ends first - it leaked in the above mentioned places, and i tried to tape it tightly with electrical tape with absolutely no effect. Then I undid it all, trimmed the ends, boiled, and reattached. Still leaking.

Is the Rhinox tube just crummy? Am I missing something obvious? There hasn't been enough pressure yet to push the CO2 out through the diffuser - could that have an impact?

I'm reading that Jardli recommends letting the diffuser sit in water for some time to saturate before using it. Could this be a part of the problem? If so, when the CO2 is more easily able to pass through the ceramic, will it stop leaking out of these connections?
 

KinderScout

Member
As far as I'm aware, ceramic diffusers need quite a high output pressure to work as it is. I'd be patient, soak the diffuser as reccommended, refit the tubing to all joints as before by trimming the ends and using hot water (in case they've split with the gas escaping). Then be adjust your output pressure to 30 and increase slowly and take your time until you see the bubbles start from your diffuser. If you still get leaks (I'm guessing you're using soapy water?) then you will need to get better CO2 tubing that's rated for a higher pressure. Last thing - as you found out tape doesn't work and you shouldn't need it.
One last thing - make sure your valveis the right way round ;) - check you can get flow by popping the end of your line in water and opening up your regulator before finally fitting the diffuser.
 
  • Thread Starter

Fishproblem

Member
KinderScout said:
As far as I'm aware, ceramic diffusers need quite a high output pressure to work as it is. I'd be patient, soak the diffuser as reccommended, refit the tubing to all joints as before by trimming the ends and using hot water (in case they've split with the gas escaping). Then be adjust your output pressure to 30 and increase slowly and take your time until you see the bubbles start from your diffuser. If you still get leaks (I'm guessing you're using soapy water?) then you will need to get better CO2 tubing that's rated for a higher pressure. Last thing - as you found out tape doesn't work and you shouldn't need it.
One last thing - make sure your valveis the right way round ;) - check you can get flow by popping the end of your line in water and opening up your regulator before finally fitting the diffuser.
I'm refitting the tubing in a few minutes - thanks for this, it's really helpful. In the event that this next attempt also fails, can you recommend a brand or distributor of better tubing? Alternatively, how can I identify what tubing is rated for a higher pressure?
 

KinderScout

Member
Fishproblem said:
I'm refitting the tubing in a few minutes - thanks for this, it's really helpful. In the event that this next attempt also fails, can you recommend a brand or distributor of better tubing? Alternatively, how can I identify what tubing is rated for a higher pressure?
mmm - I'm in the UK - I get all my CO2 kit from in Germany! Hopefully one of the many US based CO2 users will be able to help? Vishaquatics :)
 

RayClem

Member
For connecting to glass such as a glass diffuser, you need pliable tubing like heavy walled silicone tubing. There will be minor loss of CO2 through the tube, but if you only use it from your check valve to the diffuser, most of the that line will be underwater, so the CO2 is not wasted.

One thing that works well up to your check valve is the 1/4" HDPE tubing used for icemakers. The tubing will handle the pressure, the walls are thick enough so that CO2 loss is minimal and the tubing is the perfect outer diameter to seal properly with the O-rings seals in needle valves, etc. It does not work well with glass diffusers, however, because it is too rigid. You will have to transition to another type of tubing right before it enters your aquarium. It is inexpensive and readily available at your local hardware store, Home Depot, Lowes, Walmart, etc.
 

fishnovice33

Member
I use GLA tubing and it’s never failed, that have lots of colors:

 

KinderScout

Member
RayClem said:
For connecting to glass such as a glass diffuser, you need pliable tubing like heavy walled silicone tubing. There will be minor loss of CO2 through the tube, but if you only use it from your check valve to the diffuser, most of the that line will be underwater, so the CO2 is not wasted.

One thing that works well up to your check valve is the 1/4" HDPE tubing used for icemakers. The tubing will handle the pressure, the walls are thick enough so that CO2 loss is minimal and the tubing is the perfect outer diameter to seal properly with the O-rings seals in needle valves, etc. It does not work well with glass diffusers, however, because it is too rigid. You will have to transition to another type of tubing right before it enters your aquarium. It is inexpensive and readily available at your local hardware store, Home Depot, Lowes, Walmart, etc.
CO2 will make silicone tubing (basic O2 tubing) brittle over time and liable to crack and leak - especially at areas of high stress such as joins or where the tubing bends. CO2 proof poleurethane tubing is the way to go - 4/6mm (i.e. 4mm internal diameter 6mm external). Tubing isn't impervious to CO2 either - there will be diffusion across the tubing wall too over extended lengths. Less I believe with polyurethane.
 

RayClem

Member
KinderScout said:
CO2 will make silicone tubing (basic O2 tubing) brittle over time and liable to crack and leak - especially at areas of high stress such as joins or where the tubing bends. CO2 proof poleurethane tubing is the way to go - 4/6mm (i.e. 4mm internal diameter 6mm external). Tubing isn't impervious to CO2 either - there will be diffusion across the tubing wall too over extended lengths. Less I believe with polyurethane.
From a permeability standpoint, polyethylene tubing has less permeability (280 units) than polyurethane (395). That is why I suggested the use of icemaker tubing for the majority of the CO2 run. The icemaker tubing is to rigid to use with a glass diffuser, that is why I suggested the silicone tubing for the short run between the check valve and the diffuser.

Silicone tubing does have high permeability to CO2. (20,000) Thus, it should not be used for long runs. My suggestion was to use silicone only for the short distance between the check valve and the glass diffuser. Most of that distance will be submerged in the aquarium, so there will only be a few inches of silicone tubing outside where CO2 loss is possible..

Yes, silicone tubing will deteriorate over time, even when used as airline tubing. That deterioration does not occur overnight. It is necessary to remove the glass diffuser from the aquarium periodically for cleaning. as the ceramic pores will clog over time. That is an ideal opportunity to inspect the tubing and replace it if it shows signs of deterioration.

The original post complained of leaks when using the Rhinox CO2 saver tubing. Perhaps this is just an issue with the Rhinox brand. Several Amazon reviewer of the product reported similar leaks. I know the HDPE tubing/silicone tubing combination works for me. Eventually, I may decide to go with polyurethane tubing for the portion of the run from the check valve to the diffuser, but for now, the short length of silicone is working well.
 
  • Thread Starter

Fishproblem

Member
RayClem said:
The original post complained of leaks when using the Rhinox CO2 saver tubing. Perhaps this is just an issue with the Rhinox brand. Several Amazon reviewer of the product reported similar leaks. I know the HDPE tubing/silicone tubing combination works for me. Eventually, I may decide to go with polyurethane tubing for the portion of the run from the check valve to the diffuser, but for now, the short length of silicone is working well.
All the info in these recent updates has been super informative - and I realize I should have posted an update! I purchased Jardli's tubing and replaced the Rhinox brand tube with it. Immediately, the leak at the connection to the Jardli diffuser was no more.

The off brand check valve was replaced with a Dennerle check valve, and the Jardli hose fits it perfectly as well. I guess the Rhinox stuff might just not be that great.
 

RayClem

Member
Fishproblem said:
All the info in these recent updates has been super informative - and I realize I should have posted an update! I purchased Jardli's tubing and replaced the Rhinox brand tube with it. Immediately, the leak at the connection to the Jardli diffuser was no more.

The off brand check valve was replaced with a Dennerle check valve, and the Jardli hose fits it perfectly as well. I guess the Rhinox stuff might just not be that great.
I am glad your issue has been resolved.

I have a Jardli glass diffuser and inline bubble counter. They seem to be well made.
 
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