Yep Good advice ive had experience with spiders since I was young over 22 years, the brazilian white knee you see I bred that spider myself! Underneath that log with the brazilian white knee there is 7-8 inches of substrate. The humidity is 85 in the tank which I think is absoluteky perfect in my experience! I know your just trying to be a bit helpful but did u know in the wild this tarantulas burrow when it does burrow is a minimal of over 3 1/2 feet long? So it just goes to show when u hear people say 4 inches, 6 inches, 10 inches etc etc its really not deep enough for what the spider really