Leaves turning colors in week 5 of flower

[Manface5k]

Ok I'm in my 5th week of flower newbie here.1 plant leaves are turning purple on the edges the other has brown/copper spots. Now I'm making sure water/nutes are ph'd and the other day I checked the run off which was 6.6 which I read is fine. I don't use the recommended dose of nutes the bottle tells. I've heard less is more just talking to people can someone plz help me out don't want my first grow to be a waste

 

[SavageBull]

Nitrogen deficiency

 

[Erbski]

Either your lights are too low or id say its a cal def. N would be yellowing bottom to top. Cal is opposite. Ca is immobile where as N is mobile. When it comes to def of Immobile nutes will show top to bottom mobile show bottom to top

 

[Manface5k]

Either your lights are too low or id say its a cal def. N would be yellowing bottom to top. Cal is opposite. Ca is immobile where as N is mobile. When it comes to def of Immobile nutes will show top to bottom mobile show bottom to top

I think it's the lights are too low. And is there a such thing as too much cal mag?

 

[Erbski]

I think it's the lights are too low. And is there a such thing as too much cal mag?

Yes! Lol...duck duck go search calcium oxcilate it might be spelled wrong....CA can throw off K and N if theres too much. I could be wrong!