I have a 2.5 gallon kritter keeper with gravel along the bottom. I mentioned gravel because I don't know if this affects the cleaning process. Anyways, are 50% water changes twice a week with no 100% water changes unless something happens for some reason okay? My tank doesn't have a filter.
Gravel promotes the growth of good bacteria actually. (but not without a filter). But that schedule sounds fine. I would add a 100% change in every other week or so, just to make sure you get all the poo out from the gravel. The more that is left there, the faster the ammonia rises when you put new water in. The tanks not that big. I have that size kritter keeper and I just do a 100% change once a week. I wouldn't want to never do a 100% change to rinse out the gravel.