You will never do well with any Chondro hatchlings if you keep them the way you do. Do yourself a favour and buy the Complete Chondro book and follow what Greg states to do. The hatcho should be in a tub 1/2 the size you mentioned, forget the ice brick who ever told you that idea is pulling it.
I cannot believe that people outlay the money for a Green Python (or any reptile for that matter) without doing your research first. People that have no idea about Chondros, you will definately benefit from outlaying $60 bucks for Maxwells book and reading it a few times BEFORE you buy a Chondro.
Dont take this the wrong way but it is newcomers (not saying you are or will) that loose Chondros and give them a bad reputation as high end , tricky snakes. I will not sell a neonate Green Python to someone that has not researched the animal a fair bit and has a good understanding of their needs.
Assuming that the breeder that sold you this animal sold it in good shape and health (which is likely), it will get feeding within a few weeks if you house it appropriately.