I purchased 2 very similar products, footwarmers, from 2 different mfg. I know Iron, potassium chloride, and water has a very warm chem. reaction. The other prod ingredients listed Iron, water, salt, and vermiculite. I just wondered.
It depends on the Tarantula species... There are three main kinds of tarantulas when considering cage setup. Arboreal, or tree climbing, Terrestrial, or ground dwelling, and Burrowing. Arboreal tarantulas won't need much, just enough to cover 1 inch of the bottom of the cage is needed. Terrestrials will need more, about 2-3 inches worth, and Burrowers will like even more, 3-5 inches. This means, with the dimension provided (12x36x5[max depth for adult burrower]), you will need no more than 1-1/4 cubic feet or 2,160 cubic inches of substrate.
