My leopard gecko used to have red feet caused by his reptile carpet so I switched him to eco earth and they went away but then they came back and they are even more red! My leopard gecko will sit down and put his feet in the air, I can tell its hurting him! What do I do? Is it the substrate? He is prone to stuck shed, I have 3 more geckos but none of them have it or get stuck shed, what is happening??