[JustOneMore20]

Yes and no. You do want to keep nitrates under 40ppm and since yours are only 10ppm, you are good for now. There are other things in the water from the breakdown of waste that you need to get out (and can't test for), so even if your nitrates are 10ppm for months, you wouldn't want to go that long without a water change. Especially if you don't have live plants or anything that takes in the nutrients and such. Even with plants, you need to change water periodically.

I think the best thing to do for the fish is to get a schedule going. Since your nitrates stay pretty low, going a couple weeks without a change is fine. I suggest you try to change about 20% every 2 weeks. Changing water won't hurt anything. Better to be safe than sorry IMO.