Mulitple growth in my sump

[huthain]

Hey guys ive noticed this carpet looking black/dark green growth in my sump only. Also white hair looking stuff I assume harmful sponges?
Tank is relative new about a month old with new sand bed but mature rocks.

 

[EnterName]

The black growth could be a sponge if it's very hard and doesn't come off the rock easily. You might see a few pores/openings if you take a close look.

In my experience black sponges are trouble if they grow fast, so to avoid it from spreading, I personally would bleach the affected rocks. Scraping off will most likely spread it, and I'm not sure how well these sponges are in spreading through the water column if you keep waiting.

If the black growth can be removed easily or turns out to be slime then it might be some bacterial mat or something else entirely and I would need to take a close look.

Short hairs/bristles could be small tube worms (third post on page 2 if you are using the app) but I see very long ones as well, which makes me think you have something else here. Maybe it's just some algae... I'm not sure.

 

[huthain]

it looks like a slime coat honestly. I dont want to touch it so it doesn't spread to my display!

 

[Fish Fan]

I was thinking that the black growth could be a type of Cyanobacteria, that may appear darker than the usual reddish colored stuff because it's growing in the dark area of your sump.

As mentioned, try removing the black slime. If it comes up easily like a mat, then I would think it's some kind of cyano or similar bacteria pest. Use a siphon so it goes in a bucket and not in your display.

 

[huthain]

If it is cyano do I need to address it?

 

[Fish Fan]

If it is cyano do I need to address it?

I would. The danger is that it does get into your display tank, and while far from the worst pest to have in your tank, it can grow like a mat over corals, which is not good. Try just something like a turkey baster to see if it can be easily removed. If it's difficult to get it off the rock, then it's more likely to be a sponge and not a form of Cyanobacteria.