How to diagnose flucuating bubble count?

[astrphora]

Greetings.

I have dialed in my co2 so that 1bps is a 1pH drop. However, my bubble count never remains consistent, I seem to have to adjust it every few days. It goes both ways, sometimes increasing, sometimes decreasing. I have redone the entire tubing and checked for leaks a dozen or more times, neither seemed to fix the issue. I know bubble count is somewhat arbitrary but it does tell me that too little or too much co2 is being injected.

Using a GLA regulator, brass check valve, GLA diffuser. I contacted their customer service, which is usually awesome, but this time around was quite unhelpful.

I'm annoyed with it never being consistent and really need to find the solution. Any help would be greatly appreciated. Thank you.

 

[FrozenShivers]

Have you cleaned your diffuser in a bleach solution?

 

[Zeus.]

Not all regulators are created equal and needle valves can also vary the volume of air they let though day to day.
Most needle valves folk use in the hobby are cheapo ones and many find them acceptable but a few have trouble.
If I remember correct Swagelok do some very nice needle valves that excel in quality, but not cheap.

 

[MrClockOff]

In my case I was convinced that my needle valve was getting heat from shutoff valve as it was attached directly to it. As result needle valve body was expanding and releasing more gas. In the morning I could see the expected bubble count but it was increasing a lot by the end of CO2 injection end.

 

[G H Nelson]

@astrphora I first look at the working pressure needle on the dial.
If that is moving slightly you have a leak...somewhere.
Some diffusers need more working pressure....increase that.
Replace the brass check valve with a cheap plastic one, and see if that cures the erratic bubble rate.