You should probably close the solenoid if the pH is too low. The usual:
Fallback OFF (to avoid dumping CO2 if the controller is disconnected)
Set ON
if pH_reactor < 6.5 Then OFF
if pH < 7.8 then OFF
Something along these lines.
To send emails it is easy. You need to tell which email to use in the network settings.
Then for my base_email program I use the following. Note that everyday at 11am I get an email... that's just a "dead man" switch. Basically I want to make sure the email (useful after GMX stopped their free service... ask Sanjay about it ) are going out properly. The switch detection you see is a leak module.
Set OFF
If Temp > 83.0 Then ON
If Temp < 73.0 Then ON
If Swx5_1 CLOSED Then ON
If Temp < 74.0 Then ON
If Temp > 85.0 Then ON
If Power EB8_3 Off 000 Then ON
If Power EB8_4 Off 000 Then ON
If Time 11:00 to 11:01 Then ON
In the network settings, you can pick which email address to use (under AquaController email setup). You can use several. Personnally I have my private email account, and my cell phone (all modern phones have an email address attached to them: <yournumber>@<carrier_dependantdomain>).
After that you should see a "base_email" outlet in the list of outlets that can be programmed. You only need to add your code in there.