Orange marks on leaves

Hi all. I'm attempting my first grow and so far it seems to be going well 3 and a half weeks in. I noticed today some small orange marks on one plant. I'm guessing this could be a problem with heat or maybe nutes although I've been careful not to overfeed?

Temperature is between 75 and 80 degrees and i'm using a 250w CFL which is around 1 foot above the tallest plant.

Any help and advice would be great!

maybe a little splash burn? couple drops of water stayed on the leaf?

Yea that's probably what I've done. I tend to be a bit clumsy. Thanks for the quick reply

Looks like nute burn since all the plant looks really healthy just becareful with watering