Grayish white fuzz on my rocks

[karimwassef]

My 380g reef is 4 months old. Went through cyano and green hair algae but cleaned all that up. Lots of hermits, turbos, and a sea hare. Even went urchin for a while.

Water changes and heavy skimming got my rocks clean.

I just started to see hints of coralline... But now I have this light white fuzz (1/8") on my rocks. I have a lot of flow, so I don't think its bacterial. It's not green or long enough to be hair.

?? What is it and how do I get rid of it (other than with a brush)?

[karimwassef]

I also have a DSB/macro algae farm in my sump on a reverse cycle. I haven't exported any yet.

[karimwassef]

[karimwassef]

Refugium macro algae

[karimwassef]

[karimwassef]

[karimwassef]

Chrysophytes ?

[Mache62]

I have a friend with exactly the same issue developing in his tank as well. A couple months old, a few fish and some coral. He's been through the diatom stage and now this. Tagging along to see if there is anybody that can help.

[jamesamantha]

I had that....it sucked. Is that Marco rock or a similar type of rock?

It seemed bacterial in how it looked but it dies off with no light. I replaced my Marco rock and the sand. The new rock was dry rock but had an ocean origin. The Marco is a mined rock. Lots of water changes, lots of gfo, three times lights out for 3 days, and a year later my tank finally looks great.

[Michael Hoaster]

My guess (and it's just a guess) is dinoflagellates. Amphiprion mentioned that he had them, so you may want to ask him (her?).

It could also be a mixed biofilm. I think bacterial films can photosynthesize, which yours appears to be doing, with the oxygen bubbles.

Have you tested your water to see if anything's out of wack? Some stuff doesn't even need nutrients, once they get established, they can feed themselves.

I'm sure there's someone who's dealt with this, here on RC.

Crash my thread anytime, Karim. I'd still like to see a sketch of your new surge scheme. I still don't understand.

[karimwassef]

Just got back from my trip overseas- no surge work yet. I'll sketch it

[karimwassef]

It's concrete rock. I made it myself.

[whosurcaddie]

Did you happen to use oyster shells when making your rock?

[karimwassef]

Yes. I've gone through the green hair phase and the cyano phase.





That's gone with physical removal, skimming, water changes and herbivores. I was on clear rock for about a month. Then this.

If it's oyster shell leaching P and N, that would have been the surge of GHA, right?

[whosurcaddie]

I was considering making my rock but I read that they can leach phos over the lifetime of the tank. There is a new recipe now that skips on the shells for this very reason.

[jamesamantha]

Mine just wouldn't stop growing until I replaced the rock.

If you are committed to that rock I had limited success with 3 days of lights out. Gfo and water changes. Peroxide dosing seemed to help a bit.

You can scrub it off but it will come back. I left mine in for a year before I finally gave up on it. Maybe your rock will come around for you better than mine did.

It is weird stuff. Very frustrating.

[karimwassef]

If I cover it up with coralline fast enough, it should sort itself out?

[karimwassef]

Maybe 13 hours of 1200W of Metal Halide is a lot of energy for a near bare rock tank.

I am trying to accelerate my coralline growth.

[Michael Hoaster]

Are you maintaining high enough calcium levels? You've got a kick-*** kalk reactor, don't you?

Have you seen anything eating your fuzz? It seems like something would chow down on it. Maybe mithrax crabs?

But that doesn't stop the cause. You may be able to run experiments to rule out causes, one by one. For example, put a fake rock in there without oyster shells, to eliminate them as the cause.

[karimwassef]

The emerald crabs do eat it, so do all the tangs and snails and urchins.
The kalk reactor is going strong. pH is 8.25, Alk is 8.5 and Ca is 420

The difficulty with my tank is the shear surface area. I need an army of herbivores

[karimwassef]

My refugium chaeto is overflowing but I haven't removed any. They're just swarming with pods and worms. If I knew how to extract them, I'd give the chaeto away.

[Fishmommy]

I have that too in patches. I have been assuming dino, but it could of course be Chrysophytes as mentioned. Reduce silica if chrysophytes. Dino has a different cure, detailed in many threads. Either way, it's nasty stuff.

[Michael Hoaster]

Sounds like you're due for some exporting. You can probably shake a lot of pods out as you remove the chaeto.

Herbivores do a lot, but they don't address the cause.

[karimwassef]

Coincidentally, my sea hare died??

[Fishmommy]

Dinos are toxic....could be a coincidence or not