1) Make a water change to freshen up your the tanks, A half to three-quarters change will help out an extended outage. Treat the fresh water with a conditioner, "Prime" is a good product to use. Remember the County will hit the water extra hard with chloramines and or chlorine just before and after the storm. 2) Planted tank will do better as the plant will do some filtering and add oxygen to the water. 3) Do not feed your fish. Your fish will be fine without food for two weeks if necessary. If you feed and there is no filtration going on your just adding polluting agents to the water. 4) Store extra water so that you can make water changes if necessary. 5) Store extra water in frozen water bottles. So if you see your water temps going to high. Drop in a frozen water bottle to reduce the temp. Many fish or esp. corals are very sensitive to high water temps. 6) A battery operated air pump can be use to keep air powered filters going or just adding air to the tank is life saving for the fish. This is especially true if your tank is crowded with fish. Pumps can be bought at Walmarts, in the Sporting Goods section or go to BassPro Shops people use them for minnow buckets to keep the minnows alive on their boat. 7) If you have a generator your lucky, use it to get the filters operating in the tank. 8) Do not to treat the water with chemicals. The more stuff you add to the water the more chance your just going to pollute the water. If your fish are stressing, gasping for air, use an air pump, change some water or toss in some plants. If you think you might have an ammonia issue try a water conditioner or give Gabes cure a try. I am Quoting Gabe Posada, of Wattleys Discus as he had a suggestion posted to his FaceBook page. ""To all our friends and family in the fish world facing this incoming catastrophic event we ask that you stop feeding as of today and start doing 10-20% water changes every day until the day you cannot. This will eliminate a lot of the ammonia which will kill your discus once the electric fails. If you do not have a generator use hydrogen peroxide. Mix one third cup in a solo cup with tank water and distribute it evenly. I kept my tank at home alive this way for two weeks 12 years ago. I killed all the plants but the fish all survived. Praying for each and everyone of you. Best wishes and please stay safe. Gabriel Posada"