So my reef tank about 8 months old and thriving, made it thru Many problems already and finally getting fair handle on chemistry and BAAAAM!! AC unit crabs out on me. BRS warned me in many Gideon to be prepared but at least I knew what to do without pricey chiller. Came home and tank was 84,6 degrees and I panic . But fan placed and frozen water bottles and tank is now at 80.2 degrees abd managing to keep it here with a lit of work. Everything looks to be happy at the moment, hopefully no losses.