Weird brown/gray fluffy growths?

[Ameris]

No idea what these are but they’re ugly and I’m worried they’ll hurt my fish.

growing on the moss ^^ also growing on plants and filter/heater. Any ideas?

 

[Ameris]

If it helps the tank is far from new, it hasn’t had any issues recently. I’ll be testing water when I get home.

 

[MaloK]

Black Beard Algae.

Reduce nutrient in the water with water changes, vacuum substrate if possible, reduce feeding fish a little. Cut back on light period and intensify the output.

You can use liquid carbon and hydrogen peroxide dips to combat it. Fast growing plants are also a good way to deprive it from nutrients.

Depending on setup, mates and water conditions, Amano shrimps are good consumers for small tanks and SAE's are the best for large tanks.

It's not beautiful but it won't harm the fish in small quantity, but in a severe outbreak, it can lead to low oxygen level and stress fish.

 

[TC33]

So I would not say its a cause for immediate concern depending how quickly it is growing. I've had it here and there in small quantities usually on my Java Fern. I just cut the leaf off and dispose. It does spawn on other leaves but the Java Fern tends to grow new leaves as fast as I cut them.

I use a straw cleaning brush (Not sure this is the official name) to remove any that may be on non-plant items.

But then it probably depends as Malok says on if its small managable quantity or severe outbreak.