Dual stage strange leak behavior: holds pressure for a couple of months then suddenly dumps (but not into tank)

FlyingShawn

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Jun 19, 2021
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Anyone ever heard of a massive leak-dump happening, but only after running smoothly for a couple of months?

This has happened both times I've used this regulator since buying it: I attach a 5lb tank, set it for 80psi output, 4-5bps 10hr/day, leak check it with soapy water, everything's hunky-dory for a few months with the tank pressure gauge always reading >700psi whenever I happen to look at it (not often), and then... boom: I notice my in-tank diffuser isn't misting and discover the CO2 tank is reading zero. Thankfully it's not dumping INTO the tank (drop checker isn't suddenly super-yellow), but still not fun.

Shouldn't the leak be happening when the pressure is high, not when it gets lower?

PXL_20220718_233656072.jpg
 

FlyingShawn

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Jun 19, 2021
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Are you sure it isn't just running out of gas ?
In under three months running on a 55gal at 4-5bps? I'll admit this is my first pressurized CO2 system, but from everything I've read on here it seems it should last longer than that.

More importantly, shouldn't the gauge measuring the tank pressure steadily decrease as it empties? Both of my sudden dumps have gone from >700psi to zero in the span of less than a week (two tops) after hardly seeming to move at all for the first ~two months.
 

Allwissend

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It's only a 5lb tank, I'd say it's imaginable. If you checked for leaks than I don't see an issue. The tank pressure starts to lower after a majority of the liquid CO2 turns into gas. So stays rather constant for a long time then starts to drop. From there on, each use will lower the pressure so this phase does not last very long . Depending on the CO2 use rate this can last a week or two as you say.
 

FlyingShawn

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Jun 19, 2021
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Ahh, ok, I guess I'm showing my ignorance! I'm currently building a Cerges reactor, so hopefully it'll the tanks will start lasting a lot longer once it's implemented. Thanks for the help!
 

Stigigemla

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Jan 30, 2022
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Gemla Sweden
Before I had a pH controller for my "new" little tank I just counted the bubbles and checked color test pH. But when the gas was going out and the pressure went down the regulator dumped out the rest of the CO2 and lowered the pH under 5.0.
All fish died- all plants were OK. The regulator was an original AGA - made for much higher flow. I dont know but maybe Your reactor acts the same?
I installed a pH controller so now the pH never goes under 6,7.