Tank crash!

[daniella3d]

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.