Hi leslie!
Water changes can slow down a bit now you are cycled- Congratulations!! The water is now safe for Fischer.
Use the nitrate reading to see how much water you now need to change and how often. Don't let the nitrates go over 20. You'll still be looking at once a week water changes between 40 and 50% and occasional (once monthly) 80% to cut back bacterial content. If you start feeding more, you'll need to adjust that rough guide- more changes will be needed.
You only have one fish so you will probably be all-right with that kind of regime. You can change more if you want, quite safely
And well done on your hard work for a good cause too (re-your job).