Spots cooper brownish n yellow

Any one know what I need to do with this. Yesterday 5 th week in flower

Can't tell from one leaf..
Gotta pic of the plant?

Yes

Leaf tips curling up is nute burn..
www.growweedeasy.com/cannabis-plant-problems/nutrient-burn

All these deficiency's can look similar, you have to go by what youve fed to rule things out.So say you havent fed much then could be a K deficiency or say youve been giving it calmag and heavy nutes then maybe its a toxicity of something blocking something else.

Your right I got the fox farm trio I just started feeding to I waited till this week it's in the middle of week 5 I started feeding a week ago I thought it was light feed but it's only my second grow so still learning thank you I'm in prohibition land so there's no one to ask here

Give them half strength notes if your concerned. You can always give more feed but you have real problems taking it away, less is more with weed

Right on do I really need to flush it I seen a video said I should flush