All my rockwool cubes are again covered by white sugar-like fungus and some patches of green fungus.
I tried to trim off just the top layer of rockwool, but the stuff just grows back in a matter of week.

My plants are just 5 weeks old (from seedlings), What can I do????

Greatly appreciate any suggestions

Thanks;
Greg J.

Greg,
Try covering your cubes with a reflective plastic. White on one side and black on the other.
By keeping the light from reaching your cubes, you can prevent the growth of algae.
Thanks for your question.
Customer Service

covering them worked for me and a little hydogen peroxide

Thanks for your input.
Customer Service

Will foil work as well or does it need to have a black back side???

The idea here is to keep the light from reaching the cubes so as to prevent the growth of fungus; in theory, foil will work, but will be much more expensive than simple 2 sided poly.
Customer Service.

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