Hi so I have had this tank running for almost a month and I added my fish (3 platys) one week after I got the tank. Then 2 weeks later I got 5 platys (now I have 8 platys in total) I been checking the water parameters every day, now it’s been almost a month (it’s going to be a month on the 28th) and I have 4.0ppm ammonia, 1ppm nitrites, and 5.0ppm nitrates, Am I doing good? Should I do a water change? If so is a 20% water change good? Or should I do a bigger one.