Hi, I got a small 6 Gallon planted tank with control soil. Its 2 months old and 2 weeks before only I got a top light of 7500k. Suddenly now am seeing some kind of algae covering all over the substrate(PFA). From last 2 days bubbles are frequently bursting out from that covering area from the substrate It really freaks me out. Not able to understand how to stop it. Some are telling they are O2 and few are saying they are microbes, which are harmful for the fishes. I'm really worried, please someone tell me what is it? And how to stop it? NOTE: Please find the pictures attached for the reference.