There are different kinds of algae. I add spirulina to my plants as it is very beneficial. It is other wise known as blue green algae and is the healthest food in the world. The aztecs used to grow it at lake texicoco (sp?) which is know the location of mexico city. It contains caroteens (sp?) glysergic acid and crazy protein just to name a few. I add it in soil and have not tryed it on rockwool cubes but if any algae was going on them that is what I would have grow.
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