I have 2 reptile basic ve-6 racks. The tubs are 4 1/4" high and ~7 and ~14" wide (two different tubs). Will the 4" coupling\16oz deli cup combo work in these? I am currently using $0.50 food containers from wal-mart that fit great and are much bigger than the couplings would be, but they constantly tip them over. I feel like a 4" coupling would be too tall for these tubs and the snakes wouldn't be able to drink out of them.... Can anyone confirm\deny? I would really like to stop drying out tubs\beddings.