Ive seen greenhouses that bad, once they get to that point you were fkd weeks before that. You could use everything, every tactic combined, they will just come back the next day even stronger. How to keep them from returning is another thing. You will have to clear out all plant life, removing only the affected plants wont work, they will just move to the others, that or just outside waiting for you to plant them some new food. FK aphids, dont let them in, if i find a plant with a couple aphids on it, that plant gets stripped pretty heavily and as long as im not past week 2ish of flower, entire crop gets sprayed.