So if i understood correctly, even if my alk is lower than 8 at the moment, i should not start dosing until AFTER i add corals and taken levels. Will the low alk not hurt the corals initially?
You may have a jumper. Look behind the tank or on the floor around the tank. I once lost a cinnamon clown and found it months later on top of my DIY light, all dried up.
I think you may want to go slow on adding more fish until this weekend or next week. Usually we want to keep about 1 week in between so your tank can adjust to handle the additional bioload. Keep in mind you have a fish missing and probably decomposing in the tank.
Have you thought about what kind of fish and corals for your new tank?
Excellent choice of fish. I think they are all reef safe. Are you going to replace or get more Chromis? I think those 8 fish plus the Chromis are pretty much the limit of your 125g tank. Keep in mind, the Powder Blue or Blue tang will get pretty big in a few years. I would not add any more fish beyond that. Probably you should plan on adding these many fish over a 2 month period to allow your tank to adjust.
As far as corals, start with soft corals first like toad stool, or as your daughter suggested bubble coral or frog spawn. Some hard corals like Birdnest, Monti cap or monti digitatas are very easy to keep for new comers.
Simon, that's a nice setup you have with your auto feeder. Unfortunately with the way my canopy is setup, this would not be possible. I'm going to have to figure out another way. Would it be ok if i removed the canopy lid and kept the aquarium open?
I can't see why not if you don't mind some light escaping into the room. That gives you more options to do things and make maintenance easier.
Are you running your pump at max setting?