How would you characterize your philosophy on fish keeping supplies? If you're familiar with supply chain management, you're familiar with the two philosophies - Just in Case (JIC) and Just in Time (JIT). If you're not sure, just check your inventory of fish supplies. How much media do you have - mechanical, bio, and chemical? What about hoses, clamps, suction cups, connectors? Have a spare filter lying around? How about heaters? What's your PVC plumbing supply look like?
If you answered each of these while nodding your head "yes," then you're either in the JIC camp, or you've scaled back your operation and all those things listed are what you have remaining from the tanks you've taken down. If you don't have many or any of those things in your supply closet or storage bins, you've either just begun in the hobby, you maintain only one or two tanks, or you're a JIT person.
Neither is right or wrong because your philosophy depends on your budget, your proximity to a pet store/fish store, your aversion to risk, and other factors.
I am a JIC guy, no question. In fact, I keep a spare of everything, including tanks. Actually, this philosophy applies to more than just my involvement in the hobby. I keep lots of other things just in case I need them, which I will characterize as "extras." It could also be that I'm a bit OCD about having what I need when I need it.
The Cichlid Room Companion
Tropical Fish Hobbyist
American Cichlid Assoc.
African Cichlid Hub