Can a relay be controlled by a preset?

Hi. I want to make a preset to simulate day night times in an aquarium. The idea is to startup the preset , have it run for some time and after the preset is finished to activate a relay so that the main aquarium lighting comes on. Is this possible ?

yes, via multi relay usermod

can the relay in this mode be set to activate/deactivate from a preset instead of a button ?

I already answered, yes, it can.

https://kno.wled.ge/features/relay-control/

@tolisn the way to do it depends on your need
like a motor PROP
turn on the Relay first then set the preset Light
or turn on the light for a prop Figure arm and then turn on the relay that controls the arm

you need as shown in the relay control 2 presets api commands turn on and turn off that are handeld the same as presets

I have to do alot of reading. I have no idea regarding the API commands.

just copy the command over and you are done in first time @tolisn