As per the "calcium reactor" it is actually a carbon reactor. Is there no pump hooked up to it? You will want to clean it out before turning it on as I can see a bunch of detrituts sitting in there. Who knows how long the carbon has been in there as well, so I would just replace it all. When you are rinsing your new carbon to get rid of the carbon dust, make sure to use RO/di water. Otherwise you will end up wasting some of your carbon as it sucks up impurities from your tap water.
How big is this tank? Is it like a 6 foot 250? If you want to keep hard corals, you will eventually need to run all 3 lights. 2 x 250w metal halides cant possibly light 6 feet of tank effectively unless you only place corals under the two running lights.
Also, that skimmer has got to go. I am not sure what that thing is, but it looks like some old school POS lol.
With all those fish and 0 algae I would certainly expect more nitrates, or an ongoing cycle. Really wish they would have tested ammonia and nitrites so we could know for sure if there is still a cycle going on.
You have a lot of large algae grazing fish in there. What is your feeding regiment like? What types of foods are you giving them and how much?