I got backup bubblers that run on D cells (maybe 24h). I thought I was buying the type that you plug in and only switch on when the power fails, but they are manual, so I need to look for some of the automatic ones. I actually had an incident where I lost a couple of fish when the GFCI got tripped in a power blink but I didn't notice it for 24 hours and the large fish and the delicate fish both suffocated. I noticed when I heard the damsel splashing at the top of the water. Both clowns were laying on their sides on the bottom gasping, but luckily they both recovered fine when I flipped the power back on. I hadn't noticed since I left for work before the lights came on and returned after the lights went off.