I was usin insecticidal soap but the flies kept coming bak... But HOLD SHET! I bought some other insecticid spay that contained 0.01% of Pyrethrins and ~POOF~! The war waged on the flies has begun to turn tide... Victory has begun for this noob grower... Also waiting for the top inch of soil to completely dry before watering again is a win win situation, bcuz the larve thrive on wet & moist soil so they die when soil gets dry. & the roots will absorb more nutrients with a wet & dry soil cycle instead of having nutrients run off with the excess water