Aphids should always be removed as far from CP as possible. Don't mess with trying to feed them to your plants, the danger far outweighs the benefit to the plants. Aphidssssss, we hates them, my precious, we hatessss them forever, nassssty bugs. They quickly multiply and spread, and if you have them on one plant, better have a close look at the rest of your collection. Two favorite places are the undersides of the leaves, and on the flower scapes. Strike quickly and well if you find them, and then keep a closer watch on the plants: miss just a couple of them and soon you will be right back to the same problem.