I've had both for over a year now and I am happy with both - if I only could have one I'd go with the Alkatronic, however I like having two for redundancy.
Trident: Pros: If you have the apex system already this is pretty good. Measures 3 levels vs 2 (Alkatronic provides Alk and ph). 2 tubes (Saltwater and waste) for setup, pretty much plug and play, app has straight forward how to's built within the app. Regent changes/replacement are easy Cons: Regents can be hard to find. I bought enough for a year last black friday and have had trouble finding online for the past few months. Required to send into manufacturer for internal tube replacements.
Alkatronic: Pros: Buy the concentrated regent and mix your own to save a few $s (if you are really DIY, i search through forums like R2R and you can find off the shelf regent mixs that people are using). The Regent is easy to mix and fill for various containers. Depending on how frequently you want to test this can last a good amount of time. Only thing needed to replace are the pump heads or the internal pump tubing - believe about once a year (the trident requires you to send it in for maintenance). Very easy to do and you can buy direct from CoralVue. The recommend monthly calibration is easy to do. It comes with a built in dose pump (I don't know if you can use it for anything not related to dosing alk solution). If you dose something like the Fritz RPM Alk solution, this is pretty sweet. It will vary doses along with your tests until it gets to your programed level then it will auto correct dosing amounts as it "learns" what your tanks consumption level is keeping it pretty consistent. With that said, I use a calcium reactor so I no longer worry about this. Their customer support is top notch, and their different product lines are awesome (Dostronic, Master Tronic). They provide a lot of details on facebook of their product developments.
Cons: While the app is straight forward, sometimes switching between wifi connection and local blue tooth connection requires a hard reset - Ive tried to do manual tests that get delayed starts or simply don't make it to the machine.
Also, while this might have been fixed by the developer, when I set mine up a year ago I believe it was mentioned in the alktronic setup that if you use it to dose alk solution, when you first set it up if you Alk range is way off it will do a pretty large dose in an attempt to auto correct you to the correct level. So if you were at 6, and you wanted 9 ppm it'd pump in a ton causing a quick spike which could cause harm to your corals. Unless this issue has been resolved, I would not recommend starting it with this feature turned on.
