Welcome back into the hobby. It sure is like a rash that won’t go away eh? [emoji4]
Looks like you’ve got some good advice on the guts of the tank. Allow me to chime in on the test kits. I have tried them all and this is what I’ve found best from an accuracy and ease of use (read color interpretation) standpoint:
Ca & Mg: Red Sea Pro
Alk: Hanna checker
PO4: Hanna ULR Checker
NO3: Red Sea Pro. I used Salifert here for quite some time but could never interpret the colors easily. Red Sea is much much easier.
Looking forward to seeing your build come together! Cheers!
It really seems test kits have gotten way better with time so I did some research on the ones you mentioned and think those are needed so they will be added to the build list.