Hmmm I would say try a little bit more N then the usual dosage. What was the dosage PMD left you? I took 18 cutting from my 2 plants and out of the 18 I ended up with 11. I had the same problems with yellowish brownish color on the leaves. Most of my plants over came the problem and now I have nice tall lovely girls grow some thick buds. I would think the problem came from either stress or a nutrition problem. All I know the rule of the thumb which everyones knows is plants when Vegging plants need lots of Nitrogen but ur dad knows what hes doin so I'm asuming he left good instructions for feeding it would have to be a deficiency. I would go with a Flush then try to choose the problem from these 2 sites I'm going to give u and good luck:thumbsup:

PS give me ur dads feeding instructions OH i know your dad put to use the SUPERTHRIVE dont forget to use that.

http://www.weedfarmer.com/cannabis/tables_guide.php:thumbsup:

http://www.greenmanspage.com/guides/plant_abuse.html:thumbsup: