When painting your home or having a terminator come over to spray for bugs, be sure to keep your tank safe by covering the top and keeping the area well ventilated. Paint will obviously cause issues if spilled into the aquarium, and aerosolized pesticides can be sucked into your aquarium via devices like protein skimmers. When doing these or other home improvement activities, cover the top of the aquarium with plastic, open up windows and doors, turn off some of the equipment and make sure to keep the aquarium as contaminant free as possible. If paint or pesticides do get into the tank, make sure to do a water change as quickly as possible. Just make sure the new saltwater isn’t contaminated as well.