brown spots hheellpp!!!!

So im new at this and stating to get brown spots and yellow leaves .... I think the ppm was low and trying to up it.. what do you guys think? maganese dif and n dif

A picture would help

Right, pictures would help. You might find your problem here:



https://www.rollitup.org/marijuana-plant-problems/216537-self-diagnose-your-plants.html

Sorry no pic today....UM round brown spots smaller than a bb, and starts slow and then more and more....plants are one month old and one foot by one foot, they were looking great ...the ppm was low i think 300-340 .....don't i need to be at 900 or so now that the plants are older ....DWC.... GH ..nutes....400 mh

I've had that problem before, when I first started growing. It was a phosphorous and potassium deficiency for me mixed with bad pH levels. Once I got my pH corrected and started using correct nutes, everything turned green and beautiful...