HI everyone, I started an indoor aquaponics using nft systym over my 55 galon tank .I have been growing basil, lettuce, and spinach with good success . I have 2 mozambique talappia in the tank for about 6 months.I have been using frozen bloodworms and floating pellets .since ive used bloodworms would the talapia be safe to harvest .? If they would be harmful to humans , can I switch to just organic pellets for another six months to make the fish safe to eat.