Does it stick to things, or is it free floating?
If free floating, it's just aquarium detritus: decomposing plant material, fish crap, dead algae. You can vacuum it up with a siphon.
If it sticks, must be some type of algae. We would need more information about your tank in order to diagnose: substrate, lighting, fert dosing, CO2 source, full tank pic, plant stock, tank age.
If free floating, it's just aquarium detritus: decomposing plant material, fish crap, dead algae. You can vacuum it up with a siphon.
If it sticks, must be some type of algae. We would need more information about your tank in order to diagnose: substrate, lighting, fert dosing, CO2 source, full tank pic, plant stock, tank age.