So, I am a First Sergeant in the WAARNG, with over 30 years of Active Duty and National Guard service. I have been deployed four times and am ramping up for my fifth. So, I get where you are coming from. I bought in to the Apex in an effort to notify my wife if something is awry while I am away. However, my fear is that the Apex becomes more of a demand item than the tank and it has indeed had some issues since I bought in. Are you good with coding? They say it's plug and play but it's not. It mostly is, but it has its quirks. I have had to contact Apex numerous times and they are awesome. They can remote in and fix things I can't. I'm old school and can barely program my cell phone alarm. The head unit was defective right out of the box. The salinity wouldn't calibrate. They sent me a new one, with a 300 dollar deposit, which I got back. I got a PAR kit and it is problematic and I have to uninstall and reinstall it numerous times to get it working again after a power outage, or if I am doing maintenance and have to disconnect it. I have the AFS, and it works great, but is noisy. Who cares. Apex controls my Radions and MP40QDs, but again, it was challenging for me to set it all up to my liking. I also have a FMM and that is awesome to see if my return pump is doing it's thing.
Despite all of the issues, I like it. I can get on my phone and check the tank. I can see the flow, if the lights are on and check my EB832's to make sure the things that are supposed to be drawing power are drawing power and vice-versa. It has already saved the tank some hardships a couple of times, once when my heaters died (oddly enough both at the same time, on completely different circuits) and another time when the power went out for hours and I finally hauled butt home and hooked up the generator.
You keep bringing up salinity. The salinity probes for the Apex take months to work properly. They suck at the beginning. All over the place. It took mine around four months to steady out.
Now, my fear is that I leave and my wife won't know what to do when the Apex screws up or a module dies. I have a supply of timers and did not remove my power strips, so she can go back to manual if need be. My advice is that you should buy it as early as possible so you can work out the bugs, if need be.
Good luck in your endeavors. Be where you are supposed to be, when you are supposed to be there, in the proper uniform, maintain motivation, be first for everything (they go easier on the first, hard on the last, the last should have learned by now), and you will be fine. Thanks for your future service. Less than 10% of Americans do what you are about to do . Be proud of that.
V/r,
1SG T