In my fishroom I have Tiers stacked 3 tanks high... the bottom two tanks have lights mounted directly above them... but there are no lights on the top tanks... Even my established breeding pairs stop breeding when kept in the top tanks. Since lighting is the only difference I can find, I'm assuming this is the reason. It works well for me as I like to give breeding pairs a break once or twice a year.
Just a little something I've learned about lighting that I thought I'd share
I only turn the lights on about 4 hrs a day & sometimes not at all. The fish don't need them in the least and I suspect they'd rather never have the lights on. Lights are for us and algae.