I have lost 3 nice polys to suicide over the last few months. They crawled out of holes I didn't think they could fit through. I lost an 18" Ornate, A Palmas, and a Delhezi. I guess it takes to tragedy to learn a lesson, but I've remedied the situation. A Neon Tetra couldn't jump out of my Poly tanks now. Don't make the same mistake. They will find a way out. Seal it up.