yep heard of Canna alright; it was the florres, bio terra and the other that I haven't heard of; I don't use nutes; I use natural homemade feeds.google canna bio range never heard off any 1 not nowing canna range( normally the bio range is not known so much) 600w mut true draw will b around 260w I just fed them so maybe that's why dnt look hungry? I have 2 6inch fans blowing and my cf fan is up full also so air is fine and its impossible 2 get them outside im not in usa lol even half a gram here ur in court for it and no I have no way off testing the light levels either seriously google canna bio range and see what I mean no ph needing , even the tap water here is great straight out the tap its so pure infact most off ur btl water comes from here u can use the same kettle for 20 years and never have any lime scale at all
anyway it doesn't look too serious for the time being. get a close up of a leaf that looks distressed and I'm sure you'll get a more accurate diagnosis.
party on dude (I aint in the states either)