Well still not sure what was going on in my reef tank but it seems to have stabilzed a bit. Looks like the losses were not too bad as for awhile I thought i might loses everything. I did lose 2 fish and looks like to LPS corals. The rest look like they are gonna pull through. The only thing i know for sure is it looks like the Mg levels were below 1000 ppm not sure if that is what caused the crash. I thought i read somewhere if Mg levels are too low Ca can precipitate. Thanks to those of you who put in their two sense.

You lost 2 fish in a 17 gallons? how many fish did you have in there? Your temperature is very high and at that high temperature oxygen level is low, put too many fish in there and a bacteria bloom and there goes the oxygen and the fish die, plus the cloudy water from the bacterias.

That's my guess so far.

Is 17 gallons the total amount of water? that is very small and unstable to be dosing a carbone source with fish in there.

Calcium precipitation might affect the corals but it would not kill fish.