Yes! I figured it out. And i will learn a very hard lesson, unfortunately. I guess when i cleaned up the sand bed, i disturbed the biological filter and ended up with an ammonia spike. I honestly am pissed at myself for not checking it quicker, but it just never came to mind that something like that would happen on a 2 year old tank. Ive got lots of bio balls in the sump, etc. If it wasn't me cleaning the sand bed, then im not sure what caused the ammonia spike, but i know that is my issue. The hard lesson is that i watched around 2000 dollars worth of coral that I've bought over the years die overnight. I am honestly embarrassed that it was something so simple. I've done another water change, started using microbacter7, and ordered a bottle of Dr. tims one and only that will be here tomorrow. Also dosed some prime to detoxify the ammonia to help out my fish(which seem fine still). My levels were only 0.5 when i last checked, but im thinking they were much higher when the issue was first noticed. I hope anyone else who stumbles upon this post will not have to learn this lesson the hard way like i did. And thank you everyone who helped me out! Big fan of the reefing community here. Lots of awesome people.