Yep, he's done this. I mentioned to you before I think that during dry spells before, he's topped off the rain barrel from the hosepipe and left it uncovered to let the chlorine air off, and remember him doing the same with buckets of water when I was a kid.
I think he's become more resistant about water changes as he's aged than he used to be, I remember helping to gravel vac his tanks sometimes as a kid, because I found that really fun and sorta magical the way dirt would be sucked up the syphon but the gravel wasn't. My mum also remembers the old days pretty well and has said they certainly did plenty of water changes when they had the shop, but she usually got stuck with them, lol. But that belief that water changes cause harm is definitely ingrained in his brain, and he still thinks that carbon is essential. He just never removes or looks inside the filter, lol.
His tank most certainly had old tank syndrome, he had a bad crash some years ago before I knew much about tanks; just remember him telling me about so many die offs, and he didn't know what was wrong, but was probably not inclined to do water changes I'd imagine, since he thought they stress and harm the fish. He was very upset and frustrated, and thought about giving up the tank then. It's just looking back at it now I assume that's probably what happened. And it had old tank syndrome for sure when I first took it over and got sky high nitrate readings, hence the gradual spaced out smaller water changes before I dared to do a large one.
It's pretty fascinating really to see how much the hobby has changed in the last 30-50 years, and I do feel better about the tank knowing that he was doing his best according to the knowledge he had. It was a different time.
Aaaww, thank you! And he raised me to look for answers in books, and to give the best animal care possible, we always had a lot of pets when I was growing up, and still have a fair amount between my parents and I. So really, I'm just doing what he taught me to do