Hello, is anyone able to help me, please? I have grown geraniums, sweet peas and achillea from seeds. I'm thrilled with their progress ( yip, it's all new to me 😊), however, I have many tiny, black flies both on the seedlings and on the compost. I've googled the problem and it was suggested I use hydrogen peroxide 1/4 parts on the plants. Has anyone any other less drastic-sounding advice? I'm frightened the solution will kill the tender plants.