1 week old seedling yellow

This is my first grow , I am using a non soil potting mix and I germinated my seeds in paper towels ! I planted them a week ago and they started out pretty well but after a week my first 2 leaves are yellow they started turning yellow right after the 1st real leaves grew . I only fed it once, 1/4 strength 30-10-10 which is a nitro high nute. I'm from the caribbean so the temperature is pretty hot , I stick my finger in the soil and when it feels dry I water ! I have them under 2 40watt cfl until they r big enough for the closet grow room I am constructing with my HID lights mh/hps . I just bought a thermometer and ph kit gonna use that from today and c if it gets any better!!! Any help will b appreciated thanks