Biggest mistakes?

[AquaDERP]

I regret daily in this life style.

Mostly all like you guys have said...

e.g. : my first tank (after decades away from the business) I thought 60" 's gonna be more than enough... And nope it just suites one fish (of my kind) and another won't get any bigger. But then again I doubled the size to 120" and it's not enough neither! But servicing the 3T was a bit tired so I get another 72"' cause I felt that it gonna be easier to care(it's kinda OK but I can't swim with them) and now I want another 200"

Any suggestion on tank size that would fulfill the Aquarist spirit?

 

[AnthonyFish20]

I did a big water change and my heater broke so when i put around 80 degree water in the tank it shocked the fish i had killing 2 of them with the tank being around 68 degrees. Now I have a thermometer in my tanks.

 

[fishhead0103666]

Not starting bigger, rushing to get more tanks, and not taking a second to fully plan out all the details ( I thought I had though.).