# [Wet Thumb Forum]-Need help with JBJ CO2 regulator and co2 reactor



## allaboutplants (Oct 29, 2003)

Hi,

Wondering if anyone is having this problem also or has a fix for this. As you know the JBJ regulator has a fixed output, my co2 reactor is in line with my xp3 filter and there is pressure coming back out of the co2 line towards the co2 tank. For instance, if i unplug the co2 line from the reactor water would just shoot out of there. When i adjust the needle valve for a bubble count of 1 per second, after 30 seconds it will start to slow down until it stops. Very hard to explain, is there anyone out there running a JBJ regulator with a power reactor without the ph controller?


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## allaboutplants (Oct 29, 2003)

Hi,

Wondering if anyone is having this problem also or has a fix for this. As you know the JBJ regulator has a fixed output, my co2 reactor is in line with my xp3 filter and there is pressure coming back out of the co2 line towards the co2 tank. For instance, if i unplug the co2 line from the reactor water would just shoot out of there. When i adjust the needle valve for a bubble count of 1 per second, after 30 seconds it will start to slow down until it stops. Very hard to explain, is there anyone out there running a JBJ regulator with a power reactor without the ph controller?


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## allaboutplants (Oct 29, 2003)

Actually I spoke with someone at JBJ and they told me that the problem lies with the line pressure. It is made more for ceramic diffuser. I still would like to know if someone has a fix for this.


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## bharada (Apr 17, 2004)

My JBJ is feeding a DYI external reactor which is being fed by a Mag5 pump. No problem with back pressure from the pump slowing the CO2 flow rate.


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## Robert Hudson (Feb 5, 2004)

If you unplug the reactor, you shouldn't get any back pressure. The check valve should prevent any water from passing thru it...

and the fixed pressure is between 30 and 40 PSI which would seem HIGH to me for a ceramic diffusor, not low. Drifting pressure in the needlevalve has nothing to do with the fixed working pressure. That happens with most any needle valve and regulator to some extent. I have never seen it as a major problem with the JBJ regulator. If your main worry is water coming back in the tubing, simply shut off the reactor or filter before disconnecting the tubing.


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## Detox (Feb 26, 2004)

Is your external CO2 reactor inline with the filter intake or inline with the filter output?

Also where in relation to the external CO2 reactor is the CO2 input line (ie. top, bottom, top side, bottom side)?

Cheers,


Detox


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## IUnknown (Feb 24, 2004)

> quote:
> 
> Is your external CO2 reactor inline with the filter intake or inline with the filter output?


Shouldn't be on the output, so that less crud gets stuck in the reactor?

My JBJ is in the mail, so I am curious if I am going to have the same problems. My Co2 is enters at the bottom of the reactor.


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## allaboutplants (Oct 29, 2003)

My problem is that there is back line pressure pushing back to the JBJ regulator. I know the bubble counter has a check valve, that is not the problem. The problem is the JBJ regulator has to work against the back pressure. With my old regulator, I was able to adjust the gas output of the co2 tank higher.

The co2 reactor is connected to the xp3 filter's input line and the co2 injection is on top of the reactor. My reactor is tilted 20 degrees to the left.

For those who got their's to work, please show me how.


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## Rex Grigg (Jan 22, 2004)

It's been a very long while since I took any physics classes but it seems to me that with a CO2 system such as we use the pressure past the needle valve is pretty much going to be the same for a given bubble rate no matter what the pressure before the needle valve is. The needle valve is a pressure reducing device.


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## imported_BSS (Apr 14, 2004)

I have the Milwaukee unit, so there is no built-in check value with the unit. I put the reactor on the output side of my XP3, and about 2/3s of the way up my DIY reactor, I screwed a hole, inserted a check value and glued it in place. It would still seem like the output pressure of the regulator would be enough, but perhaps you could add a second check value nearer to your reactor?


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## allaboutplants (Oct 29, 2003)

I'll try putting another check valve closer to the reactor and see what happens. I will post the outcome, keeping my fingers cross.


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## Detox (Feb 26, 2004)

I run my external CO2 reactor inline on the intake of my Eheim 2215. I have the DIY CO2 reactor attached right after the water exits the tank (similar to the pic in the link below)

http://aquaticscape.com/articles/co2reactor.htm

My CO2 inlet barb is on the very top of the CO2 reactor, right beside where the water enters the reactor (the two barbs are parallel)

I run 1 bubble/sec into the reactor and have no issues at all with back pressure.

However, it should be noted I am not using the JBJ regulator.

Cheers,

Detox


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## IUnknown (Feb 24, 2004)

The only thing with having it reactor on the intake is that it seems like it would clog up quickly. The canister should be doing the filtering not the reactor. The good thing about having the reactor on the intake is that the filter turns into another reactor. My bubble rate was much lower when I had it hooked up this way. I agree that the Co2 inlet barb should always be on top to allow for the bubble to travel up against the flow, rather than with the flow and right out of the reactor.


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## Robert Hudson (Feb 5, 2004)

If I am wrong, then someone explain it to me...

You should only be getting water coming into the regulator if your pump is ON. When it is off, no pressure. When your C02 gas is on, it pushes the water back with little or no effort. It is not big deal. Same thing happens with a internal reactor. I once had the Plantguild power reactor hooked up to a bubblecounter and regulator. The tubing popped off the bubblecounter because I did not have it put on properly and water drained out from the tubing onto the floor until the water level in the tank was below the Rio 50 pump. But while connected, the gas had no problem pushing the water back. We are only talking about a very small amount of pressure. Not enough to impede the gas flow. It is not the regulator causing it, it is the pump.

Now I have been told the gas should always be fed into the top of a reactor so that the gas and water are running down not up.


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## Rex Grigg (Jan 22, 2004)

I have built several DIY reactors. And I have found that it's best if the gas is injected farther down in the reactor than at the top. I always inject the gas from 1/3 to 1/2 way down the reactor. If you really stop and think about it then it makes sense. You have a reactor vessel that's anywhere from 1.5"-2" in diameter. At most you have a 0.5" stream of water coming into the reactor. And this water is under pressure. So there's not a lot of water movement at the top of the reactor. Some people that build a reactor with the injection coming in at the top report noise from the reactor. This is due to a build up of gas at the top of the reactor.

Now think about how quickly a bubble of CO2 rises in a water column. If you inject the CO2 at the top of the reactor it's at the top of the reactor almost instantly. And the water at the top of the reactor is not all the turbulent. Now if you inject that bubble further down in the reactor you will have a bubble struggling to rise against moving water. And it will dissolve quickly. Now if you were to inject the CO2 right next to the outlet you might get bubbles sucked into it. But if they are even as much as a couple inches away the buoyancy of the gas is not going to allow them to be sucked into the outlet. Instead they are going to try and rise against the water column. 

I'm starting to wonder how many of you slept during science classes in school. Or are products of the newer Government school systems.

The water flow in a well designed reactor should enter at the top. The CO2 should enter at below that point in order to maximize contact time with the moving water. Look at a Hagen ladder. The water is basically not moving. The CO2 bubble is. And it is injected toward the bottom of the ladder to maximize contact time.

If you have the water flow from bottom to top you maximize the chance of a CO2 bubble escaping from the reactor. The water is flowing up and the gas floats. See the picture?

If you have both water and CO2 entering the top of the reactor you increase the chances of a CO2 bubble at the top of the reactor because your contact time between the CO2 bubbles and the moving water are very low. Get the picture?

Now a reactor should IMHO always go on the output side of a filter. You want filtered water in the reactor. Why? Because it's a reactor, not a filter. Also you should avoid placing any kind of sponge or floss in a powered reactor. Why? Because it's going to clog, even with filtered water. Why? Bacterial slime. I have gotten to the point where I have at most 2-3 small bio-balls in my reactors. Why? On the off chance that a bubble gets blown that far down into the reactor the bio-balls are going to either catch the bubble or create enough turbulence to break it apart.


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## allaboutplants (Oct 29, 2003)

I tried testing it without hooking the co2 line from my reactor and still the same problem. I either have a problem with the solenoid or the needle valve. Line pressure should not be an issue.

Thanks for the help everyone.


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