Brown tips are a symptom of a past deficiency.Not any big thing to worry about.I usually take scissors and clip the brown tips off my leaves once a month.Spots are different.If the spots are only on one leaf the chances are you spilled something on it or something made its way on to that leaf.Had that problem once and started watching out and it ended up one of my german sheperds liked to pee on my plants to mark his domain.After i kicked the shit out of his monster ass it stopped.If it isnt broke dont fix it!!! peace hydro.