Need some help with my pressurized CO2 system

[An t-iasg]

I've had my pressurized system for a little over a year now. I've never refilled the cylinder yet. It's been running on a 10 gallon tank. I have a Milwaukee regulator and pH controller.

Lately I've noticed that the pH is higher than the set point, and the red alarm is flashing. It will flash for a long time. The bubble rate is extremely slow. I noticed this one day and increased the CO2 a bit, turning the big black knob on the regulator just a bit. At the time I wondered if atmospheric conditions had anything to do with my needing to increase the CO2.

Today I noticed it again - high pH, flashing alarm and slow bubble rate. I increased the CO2 again. Is something malfunctioning? Could it be the solonoid, pH controller (is the little knob slipping?) or the needle valve? I calibrated the probe. It wasn't off.

Is this what happens if the cylinder is getting empty - more adjustment is needed to drive the little bit of CO2 out? By opening the main valve on the regulator more, is that what will lead to the "end of tank" dump? The cylinder still feels heavy to me and the left gauge is still right on 60.

The tank and plants are doing fine - still some diatoms from the new setup but no other algae even though the CO2 level is probably fluctuating.

 

[neilanh]

What are your pressure readings from the regulator? Both sides.

 

[Purrbox]

The cylindar should be completely open so that adjusting the large nob wouldn't make a difference, unless of course the black knob is adjust the low pressure. Generally this shouldn't need adjusting to maintain the low pressure, unless you're getting close to the end of a cylindar. If the high pressure gauge (the one that should read about 800psi until it's starting to get close to empty) is starting to go down, then this can make adjustments to either the low pressure or needle valve necessary. I find that sometimes I need to adjust my needle valves when the temps cool off or warm up as this tends to affect the pressure.

 

[An t-iasg]

We recently moved this system so I made sure again that we set it up correctly. The cylinder valve is completely open. Adjusting the black regulator knob does make a difference in the bubble rate. The left gauge reads 60 on the outer band and between 800-900 on the inner band. The right gauge is a little harder to read. It has three increments to get to 20. The needle is between the second and third increment, so I would say the reading is slightly under 10. The pH was fine this morning and the alarm is not blinking.

Of course, I know what the problem is It heard me talking about getting another CO2 system!

 

[neilanh]

haha

If you recently moved the system, it needs to resettle a bit probably. It'll take some "tweaking" here and there until it gets set just right again, very similiar to when you first set it up.

 

[An t-iasg]

Thanks, everyone,
That makes sense that it may need a little more tweaking in the new house. I'll just keep more of an eye on it.

 

[An t-iasg]

I just noticed that the right gauge is now pegged at 0 and has been for two days. The pH has been holding steady and I haven't seen the alarm flash either for a few days.

Edit: OK, I am embarrassed! The right gauge drops off to 0 when the CO2 isn't running. The gauge shows a reading only when
CO2 is going through the line.