When should i put seed in light?

i placed 2 seeds in a shot glass full of water. One sprouted a white root and the other still didnt sprout a tip. The seed that sprouted a tip is in rockwool in my cabinet recieving no light. My question is....should the seed that srpoted a tip be placed under light?? or should i wait and leave dark?

I put my seed under lights as soon as the tip came out just coverd the top of the seeds alittle with the rockwool and im at week 2 into flowering now so i dont think it will hurt it any its the nutes you dont want to start so early