The pH outlet control serves two main purposes; controlling equipment and adding redundancy to the system. Option: Fallback You'll probably want to set the fallback option to 'off' so the outlet turns off should the energy bar ever get disconnected from the base Apex module. Option: Probe Name Providing you aren't using a calcium reactor where you may have multiple pH probes, you can select 'pH' as the probe you're using TIP: Most of the time, redundancy with kalk and two part means cutting off power to the feed pumps if the pH were ever to get too high. Option: High Value Enter the high value of pH level for your tank Option: Low Value Enter the low value of pH level for your tank TIP: The high and low values are a type of hysteresis so things don't flicker on and off. Option: On When Here you will choose whether you want the 'on' to be triggered based on the high or low value. This will be based on whether you are trying to prevent your tank's pH from going above a certain pH, or ensuring it doesn't fall below a specific pH. For example, if you're setting up the outlet so your two part pump doesn't fall below 8.25, you may set your 'low value' as 8.25, your 'high value' to 8.45 and set 'on when' to 'low'. This set-up will turn the outlet off if the pH reaches your high value of 8.45, and it won't be triggered on again until it hits your low value, of 8.25. For a calcium reactor you'd want to keep the pH low enough that it can properly dissolve the media, so we'd want to do the opposite. It's common to set the pH control for the CO2 solenoid to 6.7 as the 'high' and 6.5 as the 'low', then set the 'on when' to high. This set-up will have the outlet on, allowing CO2 to be added until the pH drops below the 'low' temp of 6.5, where it will then turn off and will not be triggered on again until it reaches the 'high' value again. Hit 'send to Apex' when you're done, and your pH outlet will now be programmed. Once that's done, you can change the control type to 'Advanced' to see the code it has just written for you. This is where you could add additional actions or control. If you have questions or advice for your fellow reefers checkout the comments area down below. Don't miss our next episode, hit that subscribe button! :) Check out the entire Apex line: http://brs.li/neptuneapex Watch the whole playlist: https://www.youtube.com/playlist?list=PLBaMLrfToJyz8091y-PoECoUo5QfMGg1S Connect with us on Facebook: http://www.facebook.com/BulkReefSupply Check out our pics on Instagram: http://instagram.com/bulkreefsupply