Pyramiding is caused by a combination of insufficient heat and hydration with a possible connection to nutritional imbalance... simple.
The primary concern is keeping the animal warm with a temperature range of 80 to 100 F with water available at all times and soakings daily to every other day for tortoises under a year. If you throw in a varied diet to these conditions I can promise a good looking tortoise.
Any hay is really suitable as a substrate for Sulcata but I don't think the type really has anything to do with it's molding properties.
-----
Ed
Tortoise_Keepers-subscribe@yahoogroups.com
Trying to keep the fun in Chelonian care