Clownfish behavior related to lighting

[PasoFish89]

Hello everyone, got a clownfish question in regards to lighting.

I have 2 black ocellaris clowns in a Nuvo 10. Back in September I added them back to the tank after running the tank fallow for 76 days and keeping the clowns in QT after a copper treatment. Before I removed them to place them into QT, they swam and occupied a lot of the tank while hosting a spot where the rock meets the sand. Since coming back into the tank after treatment, I've noticed they rarely if ever venture away from their host location. It's been probably 6-7 weeks since they've been back in the tank. I'm dealing with some hair algae right now so I decided to kill the tank lights for a few days while the CUC I beefed up does work. I've noticed today that they are freely swimming around and occupying the entire tank with just ambient lighting. When I turn the lights on to 5% or as though they were just coming on in the morning, they retreat back to their spot to keep a much tighter area. They eat great and are healthy, just confused by this. Any ideas/tips to get them to venture out more or just leave it alone? Or is this typical clown behavior for daytime lighting?

 

[Dbichler]

Natural reaction all fish do this but the smaller fish tend to be faster. Think of it as survival if your going to be eaten where would you go. Lights on and off is right when fish eat in the ocean or lakes that’s why anglers prefer dusk and dawn. On the other hand though clowns that choose a spot as a host don’t venture far from their host.

 

[9975]

My two were in my 350g before any other fish and stuck to their corner for a couple days. After that, they would venture everywhere. Once I added more fish they definitely spent more time in their corner but as there get comfortable they started expanding again.

It's like @Dbichler said, lights can simulate feeding times so they want to be comfortable so they go "home".