Fuzzy stuff on the underside of rocks

[Brandon McHenry]

Hi all!

I’ve got something growing/accumulating on the underside of my rocks in one of my tanks and I can’t seem to identify it. It’s a grayish brown color and it brushes off the rocks very easily but also returns very quickly. It does not seem to grow/accumulate on the tops of the rocks, only in the shade. It does not seem to be irritating anything but it is very ugly. Any idea on what this may be and how to get rid of it? Thanks in advance!

 

[Subsea]

Can’t give you a name, but looks like you need janitors to clean it up. Try Cerith Snails & Emerald Crabs.

 

[Brandon McHenry]

Can’t give you a name, but looks like you need janitors to clean it up. Try Cerith Snails & Emerald Crabs.

I do have a few of them, not much has seemed to touch it. Do you think it is algal or detrital in nature?
My current CUC includes (IM Nuvo 40):
3 Mexican turbo snails
4 Banded trochus snails
5 Astrea snails
10 Caribbean cerith snails
10 Stocky cerith snails
25 Blue leg hermit crabs
10 Scarlet reef hermit crabs
1 Maroon hermit crab
1 Electric blue hermit crab
2 Emerald crabs
2 Skunk cleaner shrimp
1 Lawnmower blenny

 

[Subsea]

Considering it doesn’t grow on surfaces exposed to light, I doubt it’s photosynthetic algae. More likely, you should focus on detrivores for janitors: micro stars, bristle worms and pods. I suggest several different variety of copepods.

 

[Brandon McHenry]

Considering it doesn’t grow on surfaces exposed to light, I doubt it’s photosynthetic algae. More likely, you should focus on detrivores for janitors: micro stars, bristle worms and pods. I suggest several different variety of copepods.

Agreed I don’t think it’s algae either. I just recently added a few variety of copepods from Algagen (tisbe, parvocalanus, and apocyclops) maybe they are still establishing themselves. I can take a look into diversifying my detritovores as well.

 

[Brandon McHenry]

This is a close up picture of the fuzzy stuff smashed against the front glass for closer inspection.

 

[Brandon McHenry]

So I’ve seen my pod population doing very well lately (both amphipods and 3 types of copepods). Unfortunately I’ve seen no improvement with this gray stuff on my rocks even with regular brushing and weekly water changes. I’m at a loss to what this is and how to get rid of it. Does anyone from the #reefsquad have any ideas? Thanks in advance!

 

[mta_morrow]

I’m not exactly sure what it is, but I had the same thing in my first tank. I used a toothbrush and just scrubbed it off and increased flow in the tank and collected it in my filter socks.

 

[Brandon McHenry]

I’m not exactly sure what it is, but I had the same thing in my first tank. I used a toothbrush and just scrubbed it off and increased flow in the tank and collected it in my filter socks.

How long did it take to go away? I have two MP40 set to 50% NTM in my IM Nuvo 40. Every time I brush it off and do a water change it seems to come right back. Also how often did you have to brush to knock it out?

 

[mta_morrow]

How long did it take to go away? I have two MP40 set to 50% NTM in my IM Nuvo 40. Every time I brush it off and do a water change it seems to come right back. Also how often did you have to brush to knock it out?

What are you nitrates and phosphates measuring? Also how long has the tank been up and running?

 

[Brandon McHenry]

What are you nitrates and phosphates measuring? Also how long has the tank been up and running?

Nitrates are sitting between 15-20 ppm and phosphates are about 0.1 ppm (both done on salifert). The tank has been up and running for almost a year (I think 11 months).

 

[mta_morrow]

Hmmmm. Your nutrients are ok. So I would recommend keep scrubbing it off. I don’t believe anything would eat it.

Let’s try and get a few more eyes on it.

I know I had it when I was a noob and I just kept at it and after a few scrubs it was gone.

Never had it in my current tank.

#reefsquad

 

[Brandon McHenry]

Hmmmm. Your nutrients are ok. So I would recommend keep scrubbing it off. I don’t believe anything would eat it.

Let’s try and get a few more eyes on it.

I know I had it when I was a noob and I just kept at it and after a few scrubs it was gone.

Never had it in my current tank.

#reefsquad

Yeah I’d love to have more people weigh in. I’ve had 5 personal tanks over the last 8 years and I currently take care of 6 for work and this is the first time I’ve ever seen this so I’ll admit I’m stumped!

 

[Bret Brinkmann]

Curious about your lighting a d how much is reflected back up to the underside of the rocks. Maybe if more light was reflected up to it, then it wouldn't come back?

 

[Brandon McHenry]

Curious about your lighting a d how much is reflected back up to the underside of the rocks. Maybe if more light was reflected up to it, then it wouldn't come back?

Lighting for the tank is a Radion XR15 G4 Pro with a diffuser on 100% AB+ with two supplemental T5 bulbs (Blue+ and ABS) on a Geisseman retrofit. I wouldn’t say that no light is reflected up but I don’t think it’s overly bright on the underside of some of the rocks.

 

[Brandon McHenry]

I will be working on getting some better pictures of this stuff to help towards an ID but here are a few other shots.

 

[Bret Brinkmann]

I've had this stuff in my tank before. It never hurt anything and eventually went away. Not sure why but it never came back.

 

[Brandon McHenry]

I've had this stuff in my tank before. It never hurt anything and eventually went away. Not sure why but it never came back.

It’s so strange that the ID is still a mystery because so many people have said they had it in their tank at one point. Aside from it being a complete eyesore it seems like where it touches coral it has been irritating them somewhat or at the very least stopping them from growing in that direction.

 

[Bret Brinkmann]

https://www.reef2reef.com/threads/m...ment-research-for-infected-reef-tanks.610603/

Could this be it?

 

[Brandon McHenry]

https://www.reef2reef.com/threads/m...ment-research-for-infected-reef-tanks.610603/

Could this be it?

Hard to say. I may need to bring a sample to my old microbiology lab and look under the scope to see what’s going on. I’m surprised it’s not a more common pest that is easily identified.