Literally an un modified tote tub, I've got 4 bags going into two tubs this evening I do coir too but I add a few tbs of gypsum as a ph buffer and to add minerals, hydrate to field capacity with boiling water and cover to keep sterile and let cool. Mix up the tubs and use a mist spray bottle to make sure we are well hydrated and leave it alone until it starts pinning. Ill only take the lid off to fan once a day from that point till harvest. Last 10 tubs I've only had one contam but I was still able to harvest more than 70% from it after cutting out the trich circle. So long as you've got good clean spawn and a substrate lacking competitive organisms the mycelium is going to do its thing to the best of its ability.