I'm going to go to a great "pet shop" near me tomorrow to pickup a few things for the build and was wondering if I should get any substrate since this specific store is rather far away. I have 100% fertilizer free top soil and was going to use that as a substrate but understand that it might not be a good choice for the frogs. Would blending it with coco fibre be alright? I was going to use and abg mix but I'm really lazy and can't find tree fern fibre anywhere. I topsoil mixed with orchid bark and coco fibre alright? Thanks.