Need help on my first to leaves

My plants between 8/9 days old and the first set of cannabis leaves has a little yellow bit and the tips of the leaves and I haven't fed it nothing yet what would it be and the light I'm using wouldn't burn them anyone no

what soil are you using? maybe the soil is a little too hot for it right now

I used a jiffy puck

whats the temp seedlings like it warm and do you have a fan on them should be about 76degrees or little warmer for seedlings

No haven't got a fan cos I'm doing only 1 plant and it's around 71 to 74 degrees

raise temp between 75 and 80 should help the little ones a wee bit cold

Picture might help if you want anyone to actually diagnose a problem