Remember, plants need light to work, no lights no plant filter.
For future reference -- with power out, you need to tend to temperature, oxygen, and filtration.
Temp: wrap tank to maintain heat or remove hood and net top to cool down.
Oxygen: swish a net through the water, scoop water and pour, or use battery powered air pumps (airstones removed, small sponge or box filter optional)
Filtration: Open canisters and put media in shallow water, keep HOB media wet, pour tank water over each occasionally. Rinse well in tank water before restarting filter.
Add Prime or similar to the tank to handle ammonia buildup, do not feed fish.