bannanas are really not a good, nor natural food to feed box turtles because they have a very poor calcium to phosphate ratio of 1:5. A diet with a calcium ratio of 2:1 to 4:1 is ideal. How often would a wild box turtle see a bannana and eat it? A small bannana treat now and then would be fine, but not used as a significant portion of a staple diet food. Of course that can be compensated using calcium dust, but that can be tricky to keep in balance. How much cheaper does food need to be? Heck I feed my boxies with homeade food balls that are well balanced, with a wide variety of natural fresh/frozen/thawed ingredients, with complete and wide variety nutritional properties, full of vitamins and minerals, and rich in calcium, for probably $5 per turtle per year total cost. I spend that on average shoveling food in my own face in a single day.
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Jeff Benfer
gartersnakemorph.com