I Usally feed 2 hours after light’s on…
The reason for this is because about 3 hours before lights out and the plants will start to droop because their going into sleep mode and it looks like they need to be watered… which can trick you into thinking they need to be watered…
Also it’s best to do it after light’s on so they can consume as much as possible through out the day…
Also feeding at night tends to bring unwanted pests…