Second PH probe on P3

[cassedu]

Hi,
I have a PH probe on my P3 which controls my CO2 injection but I need to get a second one to check the PH of my tank
Do you know how I can do ?
Thanks
Thomas

[GHL Support]

Hello,

if you would like to have two measurements of pH, then you can buy an extension card PLM-pH (PL3 has two extension slots available) and another pH sensor.

[cassedu]

Thanks for your answer.
Actually I thought I could control PH in my tank and PH in the calcium reactor without buying an extension card but it looks I was wrong.
If I'm right it means P3 cannot control CA reactor without adding another PH probe + extension card, right ?
Basically I want to make sure PH of my tank would not go down using CA reactor....
Thanks
Thomas

[GHL Support]

If you would like to control two different pH-values in two different places, then there is not other way to use two pH sensors, that's right.
If you would like to measure one pH-value and set two different control loops for it (e.g. control pH upwards + control pH downwards with two different sockets), then for this purpose you can create a virtual sensor.