Izibani ze-QP grow light zine-firm knob, ezivumela abasebenzisi ukuthi baguqule amandla okukhanya (PPFD) ngokuya ngesigaba sokukhula kwesitshalo (okufana nokuhluma, ukukhula kwezitshalo, noma ukuqhakaza). Ubude obulengayo bungalungiselelwa izigaba ezahlukene ukuze kufinyelelwe ukukhanya okukhanyayo kanye nokuqina kokukhanya okuphelele ukuze kuhambisane nezidingo zesiteji ngasinye.
Ukukhula kwezitshalo kudinga amazinga e-PPFD ahlukene. Ku-cannabis, izigaba yilezi: Isiteji sezithombo (100-300 μmol/m²/s), Isiteji semifino (300-600 μmol/m²/s), kanye nesigaba sokuqhakaza (600-900 μmol/m²/s). Ungabheka ukusatshalaliswa kwe-PPFD kudatha yedatha futhi ulungise ukuphakama kokukhanya okukhulayo etendeni.
