Nice. That was the other issue I would've addressed, ro
water but youve got it covered.
usually mag doesnt come in a multi test kit. I personally use salifert for phosphate, magnesium, alkalinity and calcium. Much more accurate than the API versions and those are very important once you've got a tankful of corals.
The seaclone I've never heard a good thing about, suppoosed to be very difficult to adjust and get "just right" but maybe modded it will help. You can start running that whenever, it might need time to break in, my skimmers have taken about 2 weeks each to break in fully.