Hello, Bill – thanks for your post!
I have also recognized a great interest of my paros in what happens in the neighbouring tank. They were staring at each other through the glass and were more interested in watching their neighbours than in “enjoying” their own home. So I disrupted this by sliding a paper sheet between the two tanks. I have done this with all my tanks – none of my fish can see their neighbours anymore. Prying eyes from curious neighbours – who wants this? 😉