Revive after heater malfunction


left for the weekend, and came back to a mostly dead tank sitting at about 87 degrees. that was about 3 months ago. 2 clowns and my yellow tang survived, all coral 6 other fish, and most snails didnt make it. Was pretty bummed and have let the tank get pretty rough in the interim. Got these sponges as you can see, and my sand bed turns brown every day. Going to do some carbon, tims aquatics "waste-away" tims aquatics first defense" get snails back in.. Try to manually remove the sponges. any other advice?
Generally the sponges shouldn't be that harmful to the tank. Sponges can release toxins but in my experience never enough to cause an issue. That said, if the fish are in the tank still, I would just take things slow so no sudden changes occur that may affect them
Sorry for the crash- that is a bummer. Slow going is best, as stated. A mini cycle can occur as die-off fully processes; you're already watching the levels, so no news there. Frustrating!