Be careful about including calcium in the general growth & maintenance diet for inverts. Use the calcium powder to gutload if you'd like, but too much calcium in their daily diet will cause die-offs. They don't have skeleton so the calcium really doesn't help them and can cause die-offs in the cricket colonies, at least. I would assume it would be similarly bad for most inverts that don't use calcium as part of their exoskeletons (soldier fly larvae, isopods, etc.)