You know something? To be honest, with my previous 60 gallon, there's just so much to list I wouldn't have the hand strength to type it all...
Back when I kept tropicals with my dad as a boy, it was a horror scene as well (you just live and learn I suppose); instead of "treating" tap water even for top-offs, I would just let water levels evaporate and fill it back up with jars of water I left out on the bathroom counter because I was told just letting water "sit" for 24 hours or more lets all the "toxins" out...lol...this was also during the period when the "Silent Giant" air pumps were all the rage, so you know how far I'm going back here...
We also didn't really have a "lid" on this tank back then, which was part of a chrome-trimmed "wall unit" piece of furniture my dad sold in his furniture stores at the time; the fish tank was part of this piece, and he kept them on display in his stores, with fish, and got me one for my bedroom...the only "cover" this tank had was the glass shelf from the shelf above it -- leaving plenty of room for "jumpers" to get out...
Thus, we found fish the next morning dead on the carpet, notably the exotic "Elephant Noses" which never lasted 24 hours in this tank...we also mixed species that really weren't supposed to be mixed (aggressive Gouramis with Angels who ripped apart the Angels so wildly we would wake up to floating torsos in the tank)...
Fast-forward many years later to the last 60 gallon goldfish tank I kept -- what a disaster almost from day one...we didn't keep on top of water changes, I misdiagnosed a case of Ich in which I treated the whole tank with that blue melachite medicine which caused a nightmare of scenarios to begin, due to the lack of water maintenance we got horrible diatom outbreaks we could NEVER fix and patches of toxic gasses built up under the substrate to the point a bacterial infection came over the tank, I constantly rinsed my filter media under scalding hot water thus killing the BB colonies, I added salt directly to the tank making mounds of it on the gravel, I burned our carpeting when I left a heater on and walked away (I bought the heater for the misdiagnosed Ich breakout because I was advised to raise the water temp and use salt), I cracked MULTIPLE glass lids from stepping on them when I had the lids off for maintenance...
This list goes on and on...
Suffice to say...we learned A LOT before setting up this new 60 gallon...