Bummer on the Alk issues and coral losses
Very good info on the lights, i had played with the idea of setting up an LED bar with royal blue only between the T5 fixtures. Now if i do, i will go with no lenses and with dimming capabilities. I'm with you on the Hanna test- i thought they were awesone til i tested the salifert reference solution and was over 1DKH off. No hanna testers for me ever again. I'm near the end of a salifert Alk test kit and i tested the reference and was spot on, you just need to carefully clean the syringes between tests to ensure no drift.
I use the Milwauke(Martini) phosphate colorimeter and its very good and repeatable.