Hello; Other than pH the first water testing I knew much about was in the 1970's. I was taking a limnology class. We took water samples from various bodies of water. Back then for some tests I had to add a chemical immediately at the collection site to lock in the values. For other tests I just need samples in clean vials. Best I can recall it took well over an hour to run the tests back at a lab.If you were like me, there was no testing. I just changed water whenever it smelled funny or discolored. After awhile it was my habit on certain days to maintain the tanks all at once.
Also did not have a handy dandy website at my fingertips to get information from. Kinda funny in a way that even with all this new tech test kits, power filters, a wide variety of decent foods , the internet and so on there still seems to be about as many poorly run tanks as in the past. ( By that I mean most any day I find a thread about poor fish keeping on this site alone.)