@gooch: Oh, things just got worse than buying the wrong pH kit. I very stupidly managed to destroy one of my seedlings when the door to my PC box accidentally slipped out of my hand and crushed one of the seedlings. I'm afraid I'm completely hopeless when it comes to this- completely! I should have continued getting ripped off for inferior merchandise from shady dealers. Hell and damnation! With only one seedling growing yellow, perhaps, I should start all over again? I'll see what Bob says tomorrow. Much thanks for all your help, but I still think I'm hopeless!