problem????

one of my babies, the healthiest actually, has little brown spots on it upper most leaves! this is a recent occurence and i can't figure out why... I am to paranoid to post a picture so I was wondering if anyone could diagnos this w/o an image?? Is it just to close to the light? this is my tallest plant. oh also, the pH is like 5.6-5.8

You should be feeding nothing but multithrive and water at that age set the ph realy low 5.5 spray the foilige and don't overwater just give the plant a little water every few days.when plants are this young you want the lights a little higer than normal say about 30 cm above the plants.carry on feeding this mix till you have at least 2/3 sets of true leaves.i would also advice putting them into a propagator a great way of keeping the plants nice and warm but also plenty of moisture put the lid back on have vents open but spray the inside of the lid has well has plant.Once the plants have a few set of leaves start giveing them nutrients but start of low and build up to recomended dose.then get the light has close has possible put your hand between you and lights if its warm move up a tad but you want them has close has possible.This way you will end up with more bud because the internodes will be closer and the plants will be used of the lights been near.