ill get a photo uploaded jsut small amount of mint sauce colour green stuff what is this ??
You have it correct, it’s probably algae. Greenish blackish slimy stuff. It will grow easily with water and nutrients but won’t harm the plant. I see it a lot in my micro grows and it’s also common on the outside of fabric pots. When the canopy gets dense and much less light reach the coco it will stop growing.
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As Monkey said sounds like algae
Ain’t no biggy, you can easily remove top layer.. keep airflow up 👍
@chillbert I just scuff up the surface with my hands, or an old kitchen fork. If it's not getting light it will die off and do no harm.
I get it in soil too, helped massively by the intense lighting in our tents these days...algae is present in the water supply 
It just means your coco is watered properly 🙂
Thanks Guys panic Averted 😀
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