Great collection of fish, and they all appear very healthy. I'm a firm believer in large regular water changes, there's nothing better for a fish if the water parameters going in match those being drained out.
Having said that, I personally think that you are removing a few inches too much, causing stress to the fish & potential trauma when they start flopping about.
Yes, I was side track when doing wc. usually they are upright
How often do you do the water change?
I am limited to only doing it every friday