You can use mollies, scats, algae bleenies, snails, crabs, sea hares, tangs and grenades but they will not "cure" an algae problem and none of them will eat much red cyanobacteria if at all. Chemi Clean works fine. If your animals die after Chemi Clean, they were going to die anyway. If it did not kill any of my animals in two decades then it will not kill yours.
Sometimes we need a little help because our little tanks are not really mini oceans even though we think they are.
Have a great day.
Paul