I've been to both
Bryce Canyon and
Zion National Park and I really enjoyed the hike up Zions Slot Canyon. See the virtual tour link. The water can be very unpredictable so check out all the precautions but I'd recommend a day each one of these. Easy drive between them.. 5 nights will be a fine amount of time for these three.
I haven't been to Arches National Park but I'd love to hear your feedback when you return. Enjoy! Dan