Just Another Pressurized CO2 Question

[mohican]

So using a single stage regulator AND pH controller, how low can I let the cylinder pressure get before swapping? I'm less than 500 (from 900-1000 initial), but its more like 300 now.

Also, is there a way to DIY CO2 splitter instead of ordering one from Aquatek, GLA, or whomever?

Thanks everyone!

 

[fort384]

You can run it till empty, but you are probably getting very close to that. Once the pressure starts dropping, it usually isn't long before it is gone.

As far as a splitter, you can't really use any normal splitter or valve. It has to be a manifold. Otherwise, the gas will just flow to the path of least resistance, so it is really difficult to keep 2 different diffusers balanced without a manifold.

 

[mohican]

Thanks fort, I figured from the research I've done my cylinder is almost empty, just buying time and trying to figure out the best plan of attack since the company is open the same time I work, what a tragic coincidence. What sucks worse is trying to figure why my 10lb cylinder only lasted month-and-half. Leak, possible... big tank with 1 diffuser so my CO2 runs all the time, possible.

As far as a splitter, you can't really use any normal splitter or valve. It has to be a manifold. Otherwise, the gas will just flow to the path of least resistance, so it is really difficult to keep 2 different diffusers balanced without a manifold.

This I read about too but it confuses me, sort of speak, because gas should balance itself out through either path right? As for manifold, you mean something with needle valves (like name brands I mentioned) correct?

 

[fort384]

well, a manifold in and of itself doesn't necessarily have to have valves, but yes, the commercially available ones often do. The manifold is actually the center disc lookin thing:
2 Outlet CO2 Manifold Gang Valve by JBJ - AquaCave.com

I would definitely agree that a 10lb tank should last longer than a month, even on a 125 gal tank.

Yes, the gas will balance itself out, by taking the path of least resistance . So, if 1 diffuser is even slightly easier for the co2 to pass through, it will end up mostly going to that diffuser. You can make it work short term, but it requires adjustment every few days, if you just use a splitter and a couple of gate valves. Worth the few extra bucks to use a manifold.

 

[mohican]

Thanks for the site, didn't see that one! The one from aquatek has a tall "stack" that would not be able to mount on my bubble counter due to height restraint under tank. That one you showed is "short", which is what I'm looking for.

As for duration, I'm lost. I haven't sprayed my connections with anything to show bubbles for leaks. The only spot for leaks would be near regulator and/or bubble counter. What I have noticed using my glass diffuser is if the line is leaking, it won't work. I just assumed since it works, all connections are solid, may not be the case. I use CO2 grade tubing directly from counter into tank, so I'm guessing its not there. Being my first cylinder and time using pressurized CO2, I'm hoping I'll perfect it as I go along...hopefully.

 

[fort384]

yeah, just take some soapy water in a cup, and use a paint brush and paint it on to all the connections. Minor leaks do happen - I have had to tighten fittings a few times.

Also, perhaps you didn't get a good fill on the tank. Seen that happen before too.

I saw that aquatek one the other day - it is kind of goofy looking. No idea what the benefit would be of that long section on it. The 1 I linked works fine. I have used it before.

 

[mohican]

Thanks for the posts, they helped a lot!! I think that splitter will be ordered soon.

 

[fort384]

Any time!

 

[aqua_chem]

I actually use windex to test my setup for leaks, as I usually have a bottle of that laying around and ready at a moments notice.



Getting back to you original problem, you're worried about 'end of tank dump', right? It's important to recognize that the vast majority of the co2 stored in your tank is actually in the liquid form, and that the liquid is in constant equilibrium with the gas phase that you draw out the top. Because of the, your pressure won't really decrease until you are out of liquid co2, which occurs when you are already basically out of co2. Because of this, I recommend making plans to get your tank refilled as soon as the tank pressure starts going down, as you really can't predict how much you have left.

 

[mohican]

See I read that some or all of CO2 in our cylinders were liquid and when the pressure begins to drop, the gas portion has expired leaving the liquid behind. Hence our fear of end of tank dump and all that comes with it. I'm gonna swap hopefully tomorrow and "start over". So is the whole cylinder gas or liquid or both?

 

[fort384]

There is liquid in the bottom, and the rest of the volume is filled with gas. As gas exits the cylinder, there is less pressure, so more liquid can turn to gas to fill that space, equalizing the pressure again. Eventually, all the liquid turns to gas (CO2 is gas at normal temperature and pressure).

I personally always ran my tanks to empty. Never had the dump. Have heard of it happening many times though through the years.

 

[mohican]

Makes sense. Being my first time, may just cut my losses and swap tanks anyway. I'm so close to being empty anyway. I need to write this information down so when I'm near end again, I'm not panicing.

 

[mohican]

Believing anything is possible, does using a pH controller reduce likelihood of end of tank dump or make it minimal?

 

[fort384]

Theoretically it should.

I always ran a pH controller. Never had the tank dump phenomenon happen to me.

 

[aqua_chem]

A pH controlled probably would prevent the issue.

 

[mohican]

Going one step further, using this regulator and bubble counter:



How do I attach this splitter. The main attachment is male end and the main attachment coming off regulator is also male end (having taken off existing needle valve)?


2 Outlet CO2 Manifold Gang Valve by JBJ - AquaCave.com

 

[fort384]

The bubble counter needs to go after the manifold. Unscrew the bubble counter/valve and screw in the manifold.

You can then pick up one of these:
http://www.aquacave.com/2-in-1-Metal-Bubble-Counter-Check-Valve-P2010C35.aspx
So you have a counter on each needle valve.

 

[fort384]

Also I would recommend using Teflon tape on all the fittings.

 

[mohican]

I figured the counter would have to come off first; just hoping that male looking end comes off so it can screw down onto male connection coming off regulator.

Definitely gonna use teflon tape too.

 

[fort384]

The regulator should have a female end on it. The nipple coming off the needle valve / bubble counter should unscrew from the regulator. However, that same nipple on the manifold will also unscrew should you decide to use the one that is in place.