its some form of lockout,i think maybe the drip clean isnt needed every single day,but i dont know...Bubba walker clone in 3 gal chow mix. fed 2x a day with FloraNova Bloom, Drip Clean, and Roots Excel EC of 1.0-1.2. Temps 75 lights on 69 lights off.
Only pic i have unfortunately. Just sent him a text to email me some better ones so we shall see.
this is a good time to bring this up,its fine to ask for help,but one bad pic and very limited info is no help at all as far as providing a good answer,if you cut and paste the form from the sick plants forum and fill it in you are going to get a much better response.
also,even when you get an answer,you should take the time to verify it in some other way before you undertake actions suggested by people here.its impossible to remotely diagnose a plant problem from a single pic and no detailed info,and even with good info,it should be treated as a spitball guess.