rockwool

Week 2 and I just started getting these Green spots in the rockwool, should i be comcerned?
the leaf had a problem right when it came up but has since recovered nicely all other plants
are doing fine but one other plant had a spot show up on the rockwool today as well???? thanks for any tips..
Pics were taken right after a watering and they do not sit on bottom of container but a bed of media that they
will go in during flowering EBB Flow. right nowo just drip feed three times a day dyna gro fifteen minute cycles
nute strength about 450 Ph is at 5.8 .

WOW! thtnks for all the help folks/

Just some mold starting - cover the top of the cube to protect it from light and you will be straight.

it's not mold, it's green algae. Cover the top of the cubes with something so the algae can't feed off the light. problem solved.