What is this stuff? Bright yellow moldy looking stuff keeps popping up in my silver swords soil. I tried scrapping it out but it reappeared. What the heck is it? Should I be worried? The plant itself looks healthy but recently lost a couple leaves. I water once a week and the pot does have drainage. Plant is under grow light 12 hours a day. I fertilized a couple months ago with Alaska plant fish food. Originally by u/EMMAzingly- on Reddit: https://tinyurl.com/27nrhoar