If youre using a plastic bin for an indoor enclosure just put the top on and cut out holes for all your fixtures.. line the holes with tin foil so they dont melt:) that will fix your humidity and heat problems
Are you sure that that's what he poops out? Like have you seen him actually poop it out?:)
Before i used to see like a couple of strands of grass in my tort's poop, so what i did was cut the grass into small pieces.. haven't seen them in his poop since:)