Hoping I can get some help here.
I've suddenly had my whole tank afflicted by something strange and unidentifiable.
It happened very rapidly and is affecting all the different species of plants in the tank (Anubias, Java Fern, Amazon Sword mostly). It doesn't scrape off like an algae (I assume) would, so I'm wondering if it's a deficiency of some kind.
I took this picture of the leaves on one of the Anubias.
If anyone recognises it on sight, any help would be gratefully received!