temps and PH are ok, PH isnt great, but it will survive near 7, mine are always 7.
your flouros..what frequency are they? ie 2700k or 6500k or like grolux dual specrum?
someone with more know than me eeds to pipe up, but all that MG stuff looks like a massive overdose, however if they have survived in those same pots of soil since the begining the soil nutes may hopefully be dpeleted...
i reccomend a flush. check the faqs for flush solutions =)