Hi hope someone has an answer for this...We recently had a marble shower installed in slabs. Now a year later the sealant has grown mold spots in some places in the sealant, not on the surface but underneath. Is there a way to remove this sealant or to cover old sealant with a colored one that will help hide the problem? Also the glass cube wall allows water underneath and this is causing a pink stain between glass and marble. Any advice on how to deal with these things?