i'm just nervous about the idea of intentionally contaminating my tank and my grow room, plus you can always add enzymes and humic + fluvic acid which basically does the job better. Are you going aquaponics ? like with live fish and stuff? are you a microbiologist ? if not well why are you making petri dishes lol ? gonna be real hard to stay on top of a dynamic system, one night with no warning the culture can blow up suddenly you're growing mushrooms and mold... headaches bro, spare yourself ! 🚀