Like rotten eggs? That is the smell of anaerobic bacteria. Somewhat normal in dirted tanks, but can kill plants(and livestock if the hydrogen sulfide gas were to build up excessively). That is why you "stir" the dirt or poke it to release some gas. If it starts looking like roots are black and rotting off, time to investigate or start over. Sucking that part of dirt out and going forward can sometimes prevent the spread.
Too much organic in the soil, particularly when capped and too deep, leads to this. The lack of oxygen coupled with a food source(organics like rotting food, poop, and plant mulm/roots) is all it takes.
Too much organic in the soil, particularly when capped and too deep, leads to this. The lack of oxygen coupled with a food source(organics like rotting food, poop, and plant mulm/roots) is all it takes.
