Reef Tank is Suddenly Cloudy with Unhappy Coral


Reefing newb
Hi Folks,

This is my first time posting in this community, looking for some guidance from pros please...

Please see below for the details on my reef tank. The issue I face is that the tank suddenly and quickly became fairly cloudy and some on my corals and not happy at all. I'm testing like crazy to try and find the culprit.

Any suggestions please?

75g Reef Tank

Salinity – 1.024
ORP – 4476
PH – 8.48
Temp – 76
Alkalinity – 10
Calcium – 390
Ammonia/Nitrates/Nitrites = 0

Apex Controller
LED Lighting
Eshopps – RS-300 Sump
Octo Classic 150-INT Protein Skimmer
Octo AQ 2000S Skimmer Pump
Supreme Aqua-Mag 700GPH Return Pump
AquaTop MR-20 Multimedia Reactor
2 Cobalt Neo-Therm 150w Heater
Eshopps Over Flow Box 200G

Green Star Polyp
Star Polyp
Zoanthid Green Super
Toadstool Mushroom Leather

1 Rainford Goby
1 Watchman Goby
1 Yellow Clown Goby
1 Yellow Watchman Shrimp Goby
1 Domino Damsel
2 Clownfish
1 Firefish Goby
3 Green Chromis
1 Green Mandarin Dragonet
2 Lyretail Anthias
1 Yellow Tang

4 Tiger Sand Concg
1 Blue Linckia Starfish
1 Brittle Starfish
1 Chocolate Chip Starfish
1 Cleaner Shrimp
1 Coral Banded Shrimp
1 Pencil Urchin
1 Pincushion Urchin
Various Snails
Hi there!
Please do not take offense to any of my observations. I mean them with love.
How long has your tank been set up?
It is grossed overstocked. 15 fish in a 75 and all those inverts. It's too much.
What are you running in your reactor? Any carbon or media?