FWIW, there's a lot of new information/ways of thinking with Sulcatas. For one, the latest (and, so far, proving out to be most accurate) theory on pyramiding ties back to humidity/hydration, rather than protein--with the apparent cause being too little (dry climate/dehydration). Make sure you always have water available, and soak often. Dehydration has more pitfalls than just pyramiding--it may also cause renal failure and eventually death. Some theorize that the common "failure to thrive syndrome" in Sulcatas may just be mass renal failure from most being kept so dry and not having consistent access to water. You may even think about keeping his habitat humid, but at the very least do NOT keep it bone dry and don't use any of the moisture-sucking substrates like hay or rabbit pellets as bedding--that will only cause problems.
As far as temps are concerned, Michael is correct: 100F (or a little higher) basking is ideal. As for cool side/night temps, you'll want them a bit higher to avoid illness,
especially if you opt to keep yours at all humid. Ideally, you'd keep the coolest area at about 80-85F at all times. Considering the overall fluctuation in your house temps, a Ceramic Heat Emitter on a thermostat may be the best bet for keeping the enclosure outside of the basking spot up to temp.
As far as feeding, as has been stated, hatchlings rarely go for grasses/hays, which is a sulcata's primary diet. Good greens to use include collard, turnip, mustard, and dandelion greens. Watercress, Endive, and Escarole are also good. Kale can be offered every now and then for variety, but be careful--this one is quite high in oxalates (binds with calcium so they can't absorb it, also makes urates quite gritty and sometimes difficult to pass) and I have heard of tortoises becoming addicted and not wanting anything else. Lettuce can be added, sparingly, for variety's sake, but it's not terribly nutritious and is more of a filler food. Cactus pad (opuntia) is fantastic for these guys. Most tortoise keepers limit veggies, but mushrooms and squash are two great ones as treats.
As far as hay is concerned, to get it into his diet, you can try taking a softer hay, chopping it up very small, and sprinkling it over his food (a quick mist with water will make sure it sticks).
Avoid fruit. I'd even go so far as to say never feed it. It doesn't do any good that can't be found in better food options. It upsets their tummies, causes diarrhea, and if there's a parasitic infection brewing, fruit can kick it in to full force.
There are also greens to avoid. Cabbage, bok choy, and most other members of the cabbage family (collards are an exception here) should be very limited if not outright avoided. Stay away from spinach. There are a couple others--but those are the main ones to remember when you're browsing the produce aisle.
I would highly recommend browsing the various Sulcata care discussions, forum, and care sheet over at
http://tortoiseforum.org. TFO members are very open about different care styles and discussions thereof, so you should be able to find lots of information about many different options of how you can care for your Sullie. I'd track some of the specific ones down for you, but I'm having a hard enough time typing with an index finger out of commission (beardie bite, fun...). Haha. (On that same note, if there are weird typos, that's why...)
Anyway, I hope this post is helpful to you. Do make sure you're ready for the commitment--Sulcatas are most definitely unique. Large (and fast-growing if cared for right!), will bulldoze anything in their path, and definitely not one to get on a whim or just 'cause you think the idea of a pet giant tortoise is pretty cool. Research, research, research! If you decide to check out Tortoise Forum, look up the Bob threads by maggie3fan--very well-written accounts of the "adventures" that come with living with a 100 lb Sulcata.
