Beginner Gardening: H E L P! Meaningful Pot & Plant may be ruined!!!, 1 by claywoman

claywoman wrote:
I have a much-loved, BEAUTIFUL 26 yr. old Ficus benjamina I grew from seed which is happily planted in a very expensive gigantic unglazed Italian terracotta pot. It's been there about 5-6 years. There is a NASTY slick whitish-yellow scum which has been developing on various exterior areas of this pot. I keep scrubbing it off..... but it keeps coming back. It is on top of the "regular" white deposits that always develop on terracotta. I DO NOT want to have to unearth my tree! Are there any "specialists" out there that watch this beginner forum who can tell me what to do? I have just started really getting involved here and haven't been ready to financially join in yet, but will if needed, because I am beginning to see it's worth it!! CONVINCE ME!!!! H E L P.....

The dark white is the scum....also would like to add that the scum is near the top of the pot, and the rim stays damp alot of the time, although the plant is NOT overwatered; as though it takes on moisture.......odd.