My time has come
 

So my first tank nuke just happened. In my 34G, I had a peacock mantis shrimp and various other fishes+corals.
My mantis wasn't looking too great the last couple days, I thought it was a possible molt or she was dieing. And each day it looked more like death was coming. So one night at work, I get a call saying she looks like shes dead, I get home(1am) and it she was on her side not moving. I was about 99% sure she was gone, but just to kind of finalize things and since I wanted to triple check she had died, I left her in the tank till morning. Around 10am my mom wakes me up to the words " whats wrong with your tank!?" I jump out of bed, and all my fish are dead on the sand. And my peacock mantis shrimp was for sure dead as well.
I took every dead fish/mantis out of the tank. Do a 50% water change on the system, and empty the skimmer, clean any thing I can.
1 birdsnest coral is slowly starting to bleach. my candy canes kind of seem like they're (swollen/puffed/inflated ballon/ like its gonna burst?). zoas kinda closed up a little acans look alright.
Parameters; PH:7.4 Ammonia: 0.5 Nitrite:1 Nitrate:5
water params are messed up.
Im buffing the ph now, is there anything else I can do?
And I was thinking of moving my corals to a friends and cousins tank, but I dont wanna nuke their thanks if I have something toxic in my tank.

Wow sorry to hear that. Any idea what may have caused the problem before the mantis started to look bad? Have you done anything really different to your tank in the last month or so??

Sounds like something was accidently added to your tank,any little kids around?

hard to say what happened without all the info like what your water was like before hand and all that fun stuff but running as much carbon as possible wouldnt hurt:)

I think the water may I've been out of whack for a bit cause I got side tracked with exams. But I'm gonna change the carbon as soon as I get home

Get some Prime.

You didn't mention temp. Check your heaters.