Yeah too much calcium and vitamins will kill the crickets, so they die off after 48 hours and it can also be too much for the frog as well if used exclusively. Depends, maybe twice a week calcium and multivitamin dusted insects for growing frogs and once a week for adults, people have suggested and plain calcium in between to get a good Ca:P ratio on the insects, although nightcrawlers or Phoenix worms don't need calcium supplemented as they are high in calcium. I personally use repashy calcium plus and you can use this every time without the hassle of having to buy and mix up two supplements.