Q.Why are my Citrus sparse with leaves and blooms?
When I moved into my current home my citrus thrived for several years with little attention on my part. Last year I started watering on a schedule (every 2-3 weeks as well as fertilizer 2-3 times a year).
This year my grapefruit had only 3 fruits and my navel about 5-10. My tangelo (located near my house in the shade) has half of usual fruit.
This spring they have few leaves and fewer blooms – I don’t know what to do.

Certified GKH Gardening Expert
Citrus trees require lots of water and fertilizer to produce well. Here is more information that should help: https://www.gardeningknowhow.com/edible/fruits/citrus/tip-on-water-requirements-for-citrus-trees.htm
https://www.gardeningknowhow.com/edible/fruits/citrus/fertilizing-citrus-trees-best-practices-for-citrus-fertilizing.htm