I have 5 tropical fish tanks in my bedroom + i leave the lights on 24/7 in 4 of them, will this harm my fish? ?

I love going to bed watching my fish and they certainly don't seem to suffer any ill effects. The only tank which i switch the light off is the one right next to my bed as it is a bit bright if i face it while getting to sleep. Also it contains 6 tropical flounders which are generally nocturnal. I also spend quite a lot of time in the daytime watching them because i work from home and I find them really relaxing.