Does anyone know how to use the Fluval Light Dimmer and have recommended settings?

[kiteski14]

I just got a fluval 13.5 as my first tank and I'm hoping to use the stock light that the tank came with. I bought this fluval dimmer and set it, but at the local fish store the owner today told me that the lights should not be on 24/7 and that the tank should go dark at some point. Does anyone have recommended settings for this dimmer for my tank? The stock light only has two light settings and the dimmer seems pretty straightforward, but I can't find out a way to get it so the light turns off and comes back on. Any help is really appreciated!


Thanks

 

[kiteski14]

I did put the moon to 1% and still find the light to be rather bright.