to those dosing...

[Lance]

+1 Tony. My dosing system is nearly identical to yours. And like you I test once a week and top up what is needed. Fairly easy set up I think.
Had a weird scenario awhile back though: Calcium requirements went up by about 30% all of a sudden. Increased the Ca doser to make up the difference. All was fine at the new levels for a couple of months and then the calcium levels were starting to get too high. Dialed back the doser to the original setting and all is fine again. Must have been some rapid growth in the corals, clams, corraline etc. Can't say as I really noticed anything though.