So, one thing you will soon find out about aquarium keeping: not all aquarists agree. There is a lot of differing information out there. You know about water chemistry, so that is good. In the past days of aquarium keeping, it seems that it was more the norm for people to clean less and just let the tank run its course. That doesn't mean it was ever really giving the fish the best situation possible, but that is how many people did it. That is still how many people do it. You will still see all sorts of people with grungy, disgusting tanks and living fish. The advice people here have given you is solid. You need to do pwc to keep the water from turning toxic. Keep up the good work.
Let's please try to not pull this thread too far off topic, but I do also want to chime in and add that a bnp is a rather large fish for your tank size. Unfortunately, you are hindered by the petite size of the tank. I suggest going with a nerite snail instead of the bnp. I know it is not necessarily as fun to watch snails, but even my partially grown bnp would be pretty cramped such a small tank. Get a bnp someday when you have a larger tank (unless of course you are planning to upgrade sometime soonish).
Thanks, I learned so much through this thread, everyones opinion helps. Also I will make the changes with my bristlenose pleco when I get a larger tank.