interesting little plant you got there... what probably did it was when you were given the plants all in the same pot... the roots probably fought for space, and now the little guy is paying the price... i have had similar problems i geremd some seeds, popped them into the soil, and after 2 weeks... nothing had happened... so i started another germination, and planted new seeds in the pots, and removed what i thought were the old seeds... anyway, bout 3 weeks later my plants were growing great, and were probably at about 8" tall, then one day i noticed another sprout coming out BESIDE the already growing plant... so i ripped it out, and repotted it... it took a LONG time for it to actually start growing again, but it did... so just keep at it, and it should pull through also, bout your water... you dont need a PH meter if you are using Distilled