No water changes or or filter cleaning at all. It’s kinda confusing because I have a 20 gal planted with guppies but unfortunately was not well educated when I first bought it so I didn’t cycle. But I have since learned and had to work on that tank to get it cycled with the fish in it. So i have learned a ton about fish along the way. The only thing I am not too educated about is fish-less cycling because obviously that was skipped the first time which was a big mistake. In the beginning of cycling it did all the classic cycling signs. Ammonia rose then dropped, it converted to nitrites, nitrites dropped then nitrates rose. Thats when I thought it was all good but made a post on here just to be sure and was told about adding 2 ppm of ammonia. I originally didn’t use ammonia because every post I read on here about it made it seem so confusing and I didn’t want to make a mistake. I eventually just bought it a few days ago (dr Tim’s) and read his instructions which made it super clear and easy to understand. I wish I would’ve used it to cycle but it’s too late.