No name, just a lockout.
Serenade can be added to your nute solution which has no nutes yet.. lol. But YOU DON'T HAVE FUNGUS. It's just the nutes. REally.
You're going to have a hard time making a tea of oyster shell or lime, even harder trying to get it right so as not to burn the plants.
Concentrate on watering at correct pH, to the point of runoff but allowing the soil to dry between waterings, and as soon as you see the 4th set of ADULT leaves unfolding, get on it with a WEAK dose of a COMPLETE fertilizer. 1/4 what teh bottle says, and work up as more leaves appear.
I don't know what else to tell you. The overly-complex soil mix hurt you; next time, keep it simple. You may have noticed that retail salespeople get paid to sell you stuff from their store. You don't always need it. The first time my local hydro shop guy said 'You don't need that' I was like DUUDE did he REALLY just say that? OMG! Word!