Hi growers I’ve got a really bad problem which i need help with

bad smellmeans something is growing... Are you allowing substrate to mostly dry between irrigations, if not this is the cause of your problem. Could look up h2o2 application on soil.. how dilute not to kill "everything"?... But, this is a tough thing to fix mid-grow. A proper wet-dry cycle will go a long way to fixing it too. even with good habits, bad things can happen. Make sure to thoroughly disinfect anything that is reused that potentially touches the nastiness growing in your pot. Definitely don't re-use substrate or anything in it for that matter (like hydroton.. just toss it) I'd stick with it and see what happens... any major nosedive that makes it not worth continueing aside.... good learning at the least. As long as you don't cross-contaminate, i don't think you have to worry aobu tit getting to other pots... now, you see some growth on top (not algea) i'd go ahead and remove it. if it is tucked away in the substrate, probably fine as long as you don't touch it with watering wand or spout and then touch other substrates with that contaminated bit. if oyu see fuzz up top, that'll put spores into the air... theplant should be removed ASAP if any fuzz (fungus).