No choice..
I own the KHD and will order the Ion Director and Abex when released. I will also own the Trident soon fingers crossed

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Overall I do not see the Reef Bot as a competitor to the Trident. I am using this machine to test multiple tanks off one unit. The Reef Bot to me is more of a Testing station then a testing device I would hook up to a tank directly. I see every Saturday or Sunday bringing a beaker full of tank water to the Reef Bot and leaving it. a few hrs later I have all my tests done from Calcium, Po4, No3, Alk and whatever else they push out in the next year or so. This would be more testing then I have ever done for any system I have owned.
The Trident and KHD are a full ecosystem of products though that integrate quite well.
BUT...
The others can not test PO4 and NO3 these are what end up crashing my systems and causing the most issues in my personal systems. Also there are no plans with the others to test Copper and In my particular need I need to test copper 3-4 times a day in my QT.
As of now Neptune has no announced product that can test PO4 and NO3 also from what is known there is no plans on adding different tests to the Trident.