Help, My Heater Quit Working

[JW3571]

My heater stopped working sometime last night and the tank got down to 71 degrees. Are all of my corals going to die? It looks like I lost some snails and hermits but the fish are still alive. The corals have retracted but they don't look dead? I currently have two heaters the tank to warm it back up faster. It's back to 77. Any other recommendations?

[scapes]

i've got a seahorse tank that's in the low 70s with corals. you might have stressed them out, but the corals should be fine

[preef]

What kind of heater?

[Fishfish0001]

Aren't you supposed to slowly raise the temperature over a few days, and not suddenly?

[cherubfish pair]

A heater can "stick" in the on-position or off-position. It's best to use two heaters in case one fails, the other will still be working (hopefully).