Your doing what I did 16 Years ago after I got hit by a Hurricane and was without power for one week.
Judging from Your mention of an Aquarium I assume you also have a reef tank?
Anyway I ran down to a store the day before impact and bought a cheapish 6000 Watt 120/240V generator. I hooked it up the morning after the Hurricane had passed using 50ft extension cords and within hours got a knock on the door from an irate neighbor. Ignoring that I kept on going until about 10 hours later the Wife said to me that she would rather use a candle than listen to the racket anymore! Ignoring that I got to about 9PM when a small Lynch mob showed up at my front Gate and demanded that I shut off the generator. At that point I shut her down and only used it for 8 hours per day for the duration of the outage. Just enough to keep the Aquarium and fridge going on minimal life support.
After that incident I did a lot of research and ended up buying a Honda EU3000iS Generator and made an outdoor housing for it that cut down it's small amount of noise even further and also prevented any kind of weather damage with it being outdoors. I wired in a plug inside the Cabinet and plugged in a 750 ma battery tender to the battery, so it is constantly being trickle charged. The first battery lasted 8 years with this setup. I can turn her on at 1am and I cannot even hear it in the house when I am 10ft away.
The second stage of my solution was done the following week when I riped down my Electrical Panel and wired in a Reliance 120V Transfer panel.
This is the one I used, I seperated the C&D TS so I had all of them on 120V:
I also removed the Key start from the generator and made a wiring loom that bought it into the Transfer switch panel and mounted it on that Blank plastic plate on the bottom right. The last trick part was installing a 12V solenoid to pull the choke out when the key was turned and then spring returning it afterwards. For people doing this today they are in luck as a company now makes one that is plug and play, you can even get key Fab kits that remotely start the units if you want to go down that path and spend more $$.
Solenoid Link:
https://www.ebay.com/itm/123898229619?hash=item1cd8e8f373:g:63wAAOSwjLBdclz3
End result is 16 years and 451 hours of reliable service. During a blackout my wife can just turn the key and then flick the switches and everything is running in the House except for 220V devices like the AC unit and Water heater. I also left off the Microwave. I could have also wired it in but there were conditions when this could trip the Generators breaker. like if the Aquariums chiller tripped in when the Microwave and fridge were running.
The house usually draws between 900 - 1500 watts using the Genny. The gas tank holds a little over 3 gallons of gas and runs for about 12 hours on a full tank. Hondas are super reliable and the power is Inverter power so it's very clean.
Just a couple of months ago a little after her 16th year of service the Generator failed to start for the first time.
After stupidly spending 6 hours tearing it down to the bare motor I realized that it was the Low oil switch that had gotten gunked up and stuck. A quick clean fixed that but I decided with Hurricane season coming again and it was time to get a replacement. Shes a pretty old girl now and while she still looks new and works properly I am not willing to take any chances on getting stranded again after a hurricane. Her running hours are still low but her age is not.
After 6 Hurricanes I have learned a lot:
1) Noise is a big factor. Even if you don't have neighbors close by, a loud generator will drive you crazy.
2) Gas is the most reliable fuel you can find in an emergency. It's not always easy but you can find it and stock up on it.
3) A big generator is often times a liability because even it's minimum fuel consumption can be high. I had several friends with 10KW LPG generators that ran out of fuel a couple of days after the Hurricane and they could not get fuel anywhere.
Hope this helps.
