I don't have sandy's, I keep Lacies so I assume the same applies. They are meat eat eaters, so whole prey supplies everything they need. On the odd occasion I feed bits of guts (hearts,offal etc.) I add calcium powder.
When they were young and ate bugs I would add calcium powder to most meals.
As for feeding schedules ,it depends on age/size. but since you don't say how old so how do we know ?
As juvies I fed every day, then as they aged I reduced feeding to a couple of times a week.
Now they are several years old I feed twice a week during summer and less during colder months(they live outside)