Since this thread is about the Trident...here is what I hear...whether it is true or not...I can't say from personal experience...but I am mentioning some of the reasons I do not have one.
1. Easy to use and easy to see what is going on for the top 3 values.
2. Can be used for just monitoring or control if you choose. Can only control CA, Alk and Mg. Not clear how to set things up if you are using other versions of 2, 3, 4 part dosing regiments where dosing equal parts of each at any one dosing time. I use Core7. Can be really expensive and complicated to set up a 4 part by using the 2 DOS units. $600 for just the dosers in my situation.
3. Good product..but a bit quirky and temperamental. I am unsure how effective or the ability to calibrate the unit based on where you place it relative to the water source. The instructions say you cannot use a longer or shorter line of the in and out lines. All the other systems I have seen, you calibrate each to ensure accuracy...you also test that periodically.
4. Expensive to run overall...the cost of the reagents, annual tuneup, etc. - especially having to run the tests you may not really care about testing all the time...is a waste of money. I only test Ca once a week. Mg...once a month maybe.
5. Right now...availability of reagents...you are solely dependent on Apex for these reagents.
6. You must have an Apex..can't be standalone. If you lose the Apex...you lose the tests. If you want the Trident, you have to buy the Apex...that is expensive.
Personally, I have intentionally not used all systems controlled by Apex for redundancy. I have had my Apex fail in less than one year. My ATO, water change, alk testing/dosing, light schedule are not dependent on Apex. It is a pain dealing with different systems, but it does provide protection of a failure of some sort.