Hello,
Since the phoenix worms are calcium loaded but you will only be giving 10, that will be fine to go ahead & dust your crickets for him also. Is he still growing right now?
He will need calcium 4-5 days per week or one dusting per day, approximately. As long as he gets a good pinch several times per week of calcium powder either on greens/veggies or bugs, then has phoenix worms too he should be fine.
Tracie