Here's a little feedback.

Many people agree that the square footage should be equal or greater than the length of the snake. I would agree that is reasonable and that larger is better for retics. I would say that 48X30 is sufficient for a 10' snake. If your dwarf is male, you may be in good shape. Do you know the length of the parents?

If I were in that position, I would go with 72X30X18. But I don't have dwarfs. My tanks are approx. 28 square ft. (3.5'X8') for regular retics and anacondas
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steve