I tend to disagree, removing the cover/ diffuser allows every single lumen access to those leaves, and baby those plants never get enough light, most growers raise the lights come watering time, why not you...? some even smear some Vaseline on the pins to avoid any humidity, for a tighter more positive join, avoid the 13w tube... standard T5 grow is the 54w tube, thats if you want yield, with 6-8 tubes on a rack, hung from chains adjusted daily