need help plz

[fasteddy]

can any 1 help it looks like mould but not to sure its my first grow lights have been on 12/12 for a week any advice much appreciated 110764110769

[wah wah]

Is that in a rockwool cube????....could be algie....but it looks black...cover that up dood...yer stem looks fine..so far.

[fasteddy]

yer its rockwool cube and it is black aswell doesn't seem like it's affected me plants thow but i just want to get rid of it thow. so you think it could be algae......