So after making the mistake of using the container dimensions, I ended up with a rack that requires lids. I can however use the extra backboard and place under each tub. This will minimize the gap to just over 1/4 inch. I am placing a front lock system (back is getting 11" heat panels tonight) so there will be no way for them to get out even at a 1/4 inch. Lids or Lidless.. I dont have 40 snakes yet and the next one I build will be lidless at "CD height" .... This is why I built a 5-32qt cause it will become a transition rack. Thoughts...