Help ! Leafs on top turning yellow.

[Jasonj]

So this is my first grow. I got a 3x3x6 tent and I’m using a 600 hps set to 450w hps to keep it cool now that summer is almost here. Got a nice ventilation as well. My Colorado Cookies has lots of leafs with yellow tips/ some turning brown on the top but nothing serious.... and now I got the two verity tops big leafs getting/ turning with yellow spots and it’s just getting worse and worse can’t figure out what the problem is. Can you guys please help me out telling me what my problem could be please anyone?

 

[KrazyDave]

Looks like over feeding to me. Those leaves shouldn't be that dark Imo. Drop the feed down a bit and see how they do

 

[namvet25]

Looks like it could be a little nute burn from splashing feed water on the leaves.Make sure you ph all intake water near 6.5 Also start using cal/mag .