I don't see any leaf burn that would be caused by a salt buildup. A citrus tree should not be watered by over head sprinklers, and especially every day, that just to much. When a tree is greatly over watered the tree will act the same as a tree being greatly under watered. This is because the root system has so much water in it that there is little to no oxygen available to the roots. Without available oxygen a tree can't drink, even when water is available. Stop over head watering and let the root system dry out. This could be 3 to 5 days depending on the location and climate. Use your finger to determine when it is dry enough to once again to begin watering.