Your soil looks to be very peaty. Many of the premixed soils being sold are horrible! Citrus like sharp drainage (something they share with palms btw). If your mix is peaty, it is holding on to too much moisture. I would hold off on watering and repot in the Spring with a better soil. Some citrus growers advocate a "gritty mix" (I don't use it, because I grow many outside for a good part of the year, and can't keep up with watering in the stuff.) Citrus will be happy though with your standard soils used for palms (one that drains well).

P.S., Even those premixed soils marketed as being for Palms and Citrus are bad--too peaty.

P.S.2, Persian lime in container.