Solenoid cycles on CO2 to reactor: how often is too often?

[maron6977]

I personally think it's too much . If it's cycles that much - just turned down you bubble count !
Right now , I don't think mine has cycled in days .
Also , when first set up (& didn't know anything) found solenoid shut off but was still bubbling (slowly) .
So just to cover problems - turn your bubble count down . As far as I've read , should only cycle 2-3 times a day

[maron6977]

Oh Ya . Also they make 1/4" needle valves , work way better - been there, done that .

[Delphinus]

Got a link for a 1/4" valve? I'm currently using this one (which seems to have good customer feedback, but is 1/8" not 1/4")

I have the thing currently barely open. If I close it any further I don't get consistent gas flow into the reactor. I've tried lowering the regulator output pressure so that I could open the valve more, but again I get weird effects when I do that. Ie., either the bubble rate stops altogether, or the reactor effluent stops .. stuff like that.

I'm all for using less CO2 though so if the answer involves moving to a different needle valve I would consider that.

[Delphinus]

Also are you using a 1/4" regulator or do you use an adaptor to the 1/4" needle valve?

[maron6977]

Originally Posted by Delphinus

Got a link for a 1/4" valve? I'm currently using this one (which seems to have good customer feedback, but is 1/8" not 1/4")

I have the thing currently barely open. If I close it any further I don't get consistent gas flow into the reactor. I've tried lowering the regulator output pressure so that I could open the valve more, but again I get weird effects when I do that. Ie., either the bubble rate stops altogether, or the reactor effluent stops .. stuff like that.

I'm all for using less CO2 though so if the answer involves moving to a different needle valve I would consider that.

Sorry , I should have been more clear.
I use a Milwaukee reg & solenoid w/bubble counter . Glycerin in bubble counter . 1/4" needle valve for effluent. I have a Geo 612 reactor & run at a PH of 6.5.
Also just added a second chamber , so effluent runs thru vertex reactor body filled with media & overflows into sump - trying to raise tank ph , seems to work.

[Delphinus]

Ah ok, that makes more sense, thanks!

I started off with a Milwaukee regulator/solenoid/needle valve/bubble counter combo but it's now been modded enough to be its own beast. Both the needle valve and the solenoid are swapped out now. I was able to unscrew the bubble counter from the needlevalve and I use a 1/8" hose barb from an old wooden airstone as the input, and it's just mounted to my wall next to the reactor.

I've been playing around with CO2 flowrate since yesterday and I'm getting closer to steady state but still not really there. The bubble rate isn't a nice steady rate, it goes more in bursts and then has a few seconds of nothing, which I think is probably from the check valve, so that's probably OK. Over a long enough period of time the bubble rate is still consistent. My challenge now is that it really doesn't take much of an adjustment (like, seriously, a small touch of the valve) to go from "the CO2 is too fast and thus the solenoid cycles off and on too much" to "the CO2 is too slow and the despite the solenoid being on the pH is just climbing higher and higher away from the desired set point".

I'm not quite sure how I can make this better. I guess one option is lower the regulator pressure and hope this gives me a bigger sweet spot for adjustments; and another is drill the reactor and get the pH probe inside the reactor chamber itself (right now the reactor effluent empties into a little capsule that the probe sits in - so the pH measurement is actually quite slow to react to whatever is happening inside the reactor).

The more I think about it the less I like not having the probe inside the reactor, so that's probably the next thing to fix..

[Delphinus]

What psi do folks tend to have on the regulator second stage?

[maron6977]

I'll double check but I think 18PSI