CaRx pH question

[Eric23]

My tank ran out of gas yesterday morning so I turned off the regulator and disconnected the tank. This morning when I woke up I expected to see my pH controller reading the same as my system pH but it's not. My system pH is 8.0 and the water inside my reactor is reading 7.4 with no gas for 24 hours is this normal ? The effluent is set to a very low stream not a drip so there's plenty of water moving through ?

 

[Randy Holmes-Farley Verified Community Expert]

My tank ran out of gas yesterday morning so I turned off the regulator and disconnected the tank. This morning when I woke up I expected to see my pH controller reading the same as my system pH but it's not. My system pH is 8.0 and the water inside my reactor is reading 7.4 with no gas for 24 hours is this normal ? The effluent is set to a very low stream not a drip so there's plenty of water moving through ?

What does the pH normally read in the reactor?

I don't know how long it takes to flush out the system, especially if there may be CO2 gas trapped somewhere in the system that is slowly dissolving.

 

[Eric23]

What does the pH normally read in the reactor?

I don't know how long it takes to flush out the system, especially if there may be CO2 gas trapped somewhere in the system that is slowly dissolving.

I have a pH controller set to 7.2.. my regulators needle valve doesn't work well at a low bubble count so what happens is the pH goes up to 7.2 the solenoid kicks on and by the time the pH controller catches up it's released enough gas to bring the pH inside the reactor down to 6.5 or 6.4 and it usually comes back up to 7.2 within two hours

 

[Randy Holmes-Farley Verified Community Expert]

pH 7.2 may be the limit of how much the media can raise the pH by dissolving into the water in the reactor, but obviously it should rise over time when no CO2 is being added and water is flowing. If not, the meter may need recalibration.