I need to get some things straight in my head

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My levels.
At this day 06/03/08. 10:30 P.M.
Main tank lights off and fuge on.
Salinity: 1.024 using Sybon refractometer
P.H.: 8.2 -8.4 using my test kit. (API)
Calcium: 450-500 using my test kit. Turned colour as soon as last drop was added. (Red Sea)
Temp: 78F.
KH: 8dKH or 143 KH/GH. (API)
Ammonia, Nitrites @ 0 and Nitrates literally 0. (API)
Phosphates: I may be colour challenged but I read between 0.5 and 1.0 PO4/3.
50 Gallon Main with no substrate, just LR.
23 Gallon Refugium/Sump with protein skimmer.
Lots of water movement (1500 GPH with Koralia Power Heads) AND change (900 GPH).
Question:
What else should I be looking for as far as parameter readings and are my readings even close.
Live rock is over 1 year old, moved from original 29 gallon tank to this configuration 4 weeks ago.
Lots of new things growing!!
Original sand from 29 gallon in fuge with 2 mangrove plants and some of that wiry stringy stuff that is supposed to eat the nitrates if you know what I mean.
Any suggestions. I do not know my MG as I still need to get a kit.
thanx in advance to all>