refugeim lighting

[troylong45]

Is this OK 18" t8 6500k it is about 4-6" above water over a 30gal and has about 3" sand and how long should it be lit on my sump/refugeim to get the best results it has some blad grass looking stuff and some long pokie looking stuff (forgot what was called in pic below) and cheato and tons of pods and some rock (will be on reverse cycle from display)

Pic is 5 months old haven't taken new pic and the grate over top is gone and light is now hung about the same place
http://www.reefcentral.com/forums/picture.php?albumid=8339&pictureid=56878
http://www.reefcentral.com/forums/picture.php?albumid=8503&pictureid=58059

[kikoreefer]

Keep it lit opposite times of your display tank lighting to maintain steady PH