I follow a schedule of giving the first dose of P (the Bat Guano) about 2 weeks before putting the plants into the flowering light schedule. Then the first does of K (the potash) about the time I start the flowering. The plants will get another dose of P about 4 weeks after the first one and a second dose of K about 4 weeks after the first dose of K. Then about 3 weeks before harvest I give another dose of the P.Another question that i have in order to achieve proper application is, how long do they take to absorb, (guano and ash).
Do i have to top dress once at the start of flowering or wait till later?
It takes a bit of time to figure out the schedule that works for the soil, lights and set-up that you have. Sometimes what will work for one person will not work for the next. It takes some experimenting.