"The bacteria on your filter element in an established tank isn't your main source of conversion. Once your tank is established, you should be able to change entire filters without issues."1 SMALL fish for fish in cycles. Feed every 3 days.
More fish can be done, but for first timers to the hobby, 1 small fish is all you need. Just something in there producing food for the good guys. After a month, if all is good, you can add another fish, then monitor.
Goldfish aren't that bad. They can be "dirty" fish, but most times, it's overfeeding. People always want to make sure their little.fella is getting enough to eat, forgetting that 3 feedings a day ain't how nature works. We had a feeder one time grow to about 6 inches. Didn't cause any overloads in the tank. Was the craziest goldfish I ever saw.
As.for washing.media in tap.water......
If you need to clean your filter element, you're over feeding. Either that or you're over stocked.
That being said...
When I do clean mine, I use tap water every time.
The bacteria on your filter element in an established tank isn't your main source of conversion. Once your tank is established, you should be able to change entire filters without issues.
I will never understand why people have this massive obsession with filters. They provide more than just their miniscule bacterial conversion of chemicals.
Any links you can provide from reputable sources to back up this claim?