GE appears to have renamed their silicone.If you google GE silicone, they have Silicone 1 kitchen & bath which has mildewcide. <This is not the same as the old GE I.> I havn't been to a HW store to see if this is true.
Anyway, use 100% clear silicone Door & Window (it is now calls Silicone 2 on some website?). There should be no mention of anything about mold & mildew.
80 gal FW with 30 gal DIY wet/dry/sump.
9 fancy golds, 1 hillstream loaches, 1 rubber-lip pleco (C. thomasi), 3 SAEs, small school of white cloud minnows, planted.