It isn't a steadfast rule with me either
Fish get used to & like routine - they seem to know when feeding time is & lights on/off & it's funny & may be my imagination, but they seem to know when a p.w.c. is due, anticipating it.
Oh! that sounds beautiful, I love the look of frost & how it makes everthing seem fresh & clean.
Hot & Sticky! definitely - although this summer wasn't too bad-it was very humid though which makes it feel hotter.