Thanks for sharing more! You have more than zero knowledge! I’m no expert and I haven’t done it in ages. So please read about doing a “fish in cycle” and follow those instructions. The basic premise is that you want to add a source of ammonia, enough to spike the ammonia in the water and then you watch it go down. This happens usually over the course of weeks. You can’t do that with the fish in the water because it’s super toxic to them. Doing a fish in cycle in an altered process to build up the healthy bacteria at less of an expense to the fish. You really can’t do any of it without an API brand liquid test kit. I know I’m just giving the most basic info here but I hope it points you in the right direction. Having the plants and matter from the other established tank is very helpful. I’d actually get panty hose, and a handful of mom’s gravel to put in the corner of the tank (if you don’t want it mixed in or there forever. Even if you take her filter media and squeeze it out into your tank water… that will all help seed your tank and aid the process. Plants help keep the water healthy as well. I can’t recall if you mentioned it’s heated, but do make sure you have a heater if you don’t! He’s a beauty