So I just started my grow, and i have a 30 gallon rubbermade tote holding my nutrient water. The water is at constant 50 degree ferenheit, and there is a good airstone circulating a goodamount of air through, and of course i keep the lid on so its dark. 2 days later I keep smelling something foul, So i lifted the lid on my nute water, and it turns out there was a bad smell comming from that. Is this normal? If not i have some serious work cut out for me. thanks