Shells and coral turning green

[karimwassef]

I posted this in the general reef forum but thought some chemistry experts may be able to help with this too?

I have a combination or concrete rock, live rock, dead coral, large shells and PVC pipes.

My tank is stabilized and about 8 months old or so. I went through cyano, hair algae, diatom blooms, etc... Now I have no algae and my parameters are good. I don't feed often but there's enough fuzz to keep my snails, crabs and tangs ok.

However, my rockwork that should have coralline growing on it is turning green. This isn't hair or bacteria. My snails graze right over it and the pigment is still deeply ingrained. Dead corals and shells start white but turn green the same way. I can't scrub it off with a brush either.

There are specs of coralline, but it's growing very slowly.

The one section that is immune to the coloration is the PVC. Here, it just white and speckled with coralline circles.

The glass is easy to clean with a magnet except around the edges where a tough green algae growth needs to be scraped.

I know this must be some kind of micro algae that is very small and embedded. How do I get rid of it or get my coralline to grow over it faster?

pH 8.2
Alk 9.5 dKH
Ca 500ppm
Mg 1500ppm
NO3 zero
PO4 zero
NO2 zero
NH4 zero

Help.

[karimwassef]

And I have plenty of lighting 3x400W MH (12K) + 2x200W LED (blue/purple) - it's a 380g DT 8' long.

[karimwassef]

[karimwassef]

I researched it and got endolithic algae?

[bertoni]

I've seen similar algae in other tank shots, and I might have had something somewhat similar in a few new tanks of mine, but I don't have any specific recommendations. Whatever was growing in my system went away fairly quickly, so I never did any research.

[karimwassef]

This is persistent for a couple of months.

[andy01748]

From http://www.reefcleaners.org/coralline

"Coralline comes in many shades and colors, and one of the fastest growing encrusting coralline species likely to be encountered in aquaria are green in color and may make you think you have a type of nuisance algae growing on your rocks."

[karimwassef]

It's not coralline. Look at the pics. Is there a coralline growth edge? Is it playing, encrusting or branching?

[karimwassef]

It looks similar to what's on the glass edge? Except the glass can be scraped off because it can't dig in.

[karimwassef]

Look at the PVC and dead coral skeleton

[karimwassef]

some more history. I had a couple of painful events-

I believe I had dinos and fish disease, so I added a 40W UV sterilizer running at very low flow <400gph. I was also running at a pH of 8.6 for a couple of months and using hydrogen peroxide. It's gone now, but I've kept the UV on.

That was intentional. The unfortunate accident was my skimmer going wild while I was traveling. My salinity dropped to near freshwater killing much of the life in the tank. This lasted a week. Salinity is back to 35ppm now.

Not sure if that has any bearing on my green rocks. They were already tinted green, but now it's getting worse.

[karimwassef]

This shows pink coralline, green coralline and then the green pigmentation ... Different looks

[karimwassef]

In the absence of identification... I want to encourage my pink and red or purple to take over this icky green pigment.

What do I need to change?

All I can think of as variables are water chemistry, flow and lighting?

[karimwassef]

I've also been feeding phyto from seachem. It's the same greenish tint. Could that be impacting it?

[CStrickland]

Sometimes an urchin will go for stuff that other CuC can't chew off the rocks as well. They have better teeth.
I though green coralline at first too, but it would take more elbow grease to get off the glass. I don't think it is a common algae either, kinda lichen-ish... I'm stumped.

Do you have any reason to think your water chem / flow / lighting is off? I would think if there were high nutrients your hair algae wouldn't have gone away like they did. But the timeline might be important, like if everything settled down, and then the sad things happened to set you back. How long ago was your skimmer calamity? It might go away without intervention like Bertoni said if things are still settling down.

Is it just ugly, or does it seem to interfere like growing over your frags and killing them?

[CStrickland]

Double post, sorry!

[karimwassef]

The calamity was about a month ago, but the tinting started before the event.

I had urchins (in the sump now) in the DT. I removed them to encourage coralline.

My rocks were horribly overgrown with hair a couple of months into setting it up. My skimmer wasn't tuned and my macroalgae scrubber refugium was still getting established.





That went away ...



Then I had cyano and dino





Gradual improvements...



And now green tinted rock

[karimwassef]

I don't think there's anything wrong with my chemistry, flow or lighting. Until my disaster, my hard corals were growing well. They're all recovering from being damaged, but it's slow.

I've had a very hard time keeping zoas or Xenia - not enough nutrients I guess.

I can't get rapid coralline growth.

My fish look healthy and my snails are recovering well from the dino event.

All my crabs died with the exception of the hermits (dino poisoning + salinity crash)

I have one LPS (torch) also in recovery. It was about to bud before the salinity crash.

Variables I suspect may effect the tint:

1. UV sterilizer - still on due to fear of dino return. Could it be giving an advantage to the burrowing algae?

2. Skimmer off time - I cut my skimmer for 4 hours mid-day. The intent is to give surface plankton a window where they're not actively exported. It was off at night, but my dino event drove a reversal to clear the muck. Also running more dry since the salinity disaster.

3. pH - going from 8.6 to 8.4 to 8.2 is a stretch. Could that favor one type of algae? I drip kalk to keep pH constant. Reducing the pH means less dripping, but Alk and Ca are actually better now.

4. Feeding - is feeding phyto a factor?

5. H2O2 - I stopped dosing peroxide. Could that have been limiting this algae.

6. Flow - my surge has been online/offline as I tune the system. My powerheads still keep the flow strong, but nothing like a surge.

7. Light - redoing my LED fixture. All halides for the last couple of weeks.

8. Temp - I was running cool until about 2 months ago (73-74). I raised the temp to 76-77.

[karimwassef]

Here's some pics from the overflow showing different colors of coralline and the pigmenting other algae

[ReyR]

Following your thread. I'm stumped. It kind of does look like lichen.
I myself I think I'm going through a Dino phase now. I've been dosing peroxide as well. Were you doing it for Dinos? Been thinking of a UV sterilizer too. Sorry didn't mean to ask to many questions away from your search.

[bertoni]

Sorry, I thought I responded to the older post.

I don't know exactly what the pest is, so I don't know what might encourage it. An urchin might eat it, although it'd eat coralline, too.

[jminick2]

have you tried running GFO ? with all that algae of course your phosphates are going to read 0, or lowering lighting period? Coralline doesn't like really bright lights it might give it the edge to take over that green crap.

[karimwassef]

I don't have algae and I do have a GFO and a macroalgae scrubber. The hair algae is from 6 months ago.

I used UV, blackouts, 8.6pH and peroxide to fight dinos but I expect my freshwater disaster probably had a hand in clearing them too.

I did notice that the pink coralline grows in the shade in my tank.

[jminick2]

Originally Posted by karimwassef

I don't have algae and I do have a GFO and a macroalgae scrubber. The hair algae is from 6 months ago.

I used UV, blackouts, 8.6pH and peroxide to fight dinos but I expect my freshwater disaster probably had a hand in clearing them too.

I did notice that the pink coralline grows in the shade in my tank.

I was talking about that green stuff being the algae. The stuff that no one knows what it is

[Savant]

does it only look green when the tank lights are off?