The obvious first concern is for you and your family. Stay safe. You can replace fish easier than family! (Yea, I wrote that) Stock up on things you may need as with power outages, most stores stop selling because cash registers don't work and gas pumps can't pump. Keep refrigerators and freezers closed as much as possible. Unless you cook with gas, make sure you have plenty of propane for the gas grill as you could be cooking meals outside. If you have any extra freezer space, buy some ice for cooler(s) as the fridge will only stay cold enough for a short time...and use any refrigerated food first as it will go bad as the temp in the fridge drops. Even if the bags of ice stay in the freezer, they will help frozen food stay frozen longer.
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As for the tanks, at least it's not winter in the north in an all electric house!
If you do lose power, you'll want to get those battery operated air systems up and running. You'll want to unplug any external filters so foul water isn't pumped back into the tank when the power comes back on. You'll also want to get any bio media from any external filters (HOB or canisters) into the tanks, perhaps sitting on top of bubblers to keep water flowing through the media. Feed very, very lightly as less food = less waste and better water quality.
For the most part, that's all you can do.