Marco rocks and algae

[CloudReefer]

Hello

My system has been up for 3 years and I am extremely frustrated with hair algae. This is the first system I have had with an algae problem like this and hoping I can get some help.

I have TBS live rock and dry marco rock in my system. I don't have algae on the live rock at all. I've always used 100% live rock and never tried dry until this tank.

The marco rock's surface is covered in coralline, with no pest algae at all. However, every single hole, crack, pore and opening has hair algae growing out of it. I have scrubbed it with toothbrushes for 2 years.

The issue is not my water quality. My nitrates and phosphates are stable and have barely moved for 2 years. Nitrates usually around 10, and phosphates 0.1-0.2. Less than 0.1 phos and my corals start to close up and look like crap. Nitrates less than about a 6 results in the same issue.

The issue is not my CUC. I have so many slugs, crabs and snails that I have to feed supplemental nori or they start to die. I see my crabs especially eating some of the hair algae, but they don't really reach into the holes to grab it often. And besides, one strand of it seems to fill them up completely for days.

The algae does not grow quickly. It just grows in places where nothing can apparently get to it. I have used pipe cleaners and all sorts of brushes to get into every single crack and hole, and after almost 2 years of this the algae is getting thicker and worse. My corals have grown to the point that it is getting extremely difficult to get in and scrub the algae without breaking corals.

I'm also trying to avoid removing the marco rock as they have a ton of bivalves, worms etc. living in it.

I have a 75g, 2'x3' tank so have been reluctant to add any sort of tang to the tank but I am reconsidering this as I don't know what else to do. Appreciate any advice.

Thanks!

 

[lapin]

I have 100% dry Marco rock. I did cure it for 2 months in 100gallon stock tanks. Adding left over rotifer and pod water every week at change out time.
At about year 2 or 3 I had a lot of hair algae. It was all on my glass (acrylic). I do have a rock boring urchin so maybe it kept it off the rock. I also had bryopsis. However my lawnmower loved the stuff and ate it until it was gone. I did buy a sea cucumber for hair on the glass . When it was gone I traded it back in.
Good luck with your issue

 

[CloudReefer]

I have 100% dry Marco rock. I did cure it for 2 months in 100gallon stock tanks. Adding left over rotifer and pod water every week at change out time.
At about year 2 or 3 I had a lot of hair algae. It was all on my glass (acrylic). I do have a rock boring urchin so maybe it kept it off the rock. I also had bryopsis. However my lawnmower loved the stuff and ate it until it was gone. I did buy a sea cucumber for hair on the glass . When it was gone I traded it back in.
Good luck with your issue

Thanks for the response!

I have very little algae anywhere in my tank except in the holes and cracks of my rocks. I have an urchin, sea hare, tons of snails and lots of crabs of all types.

The urchin eats it, but only if it's on the surface of the rock. It can't get into any of the crevices. My sea hare (Dolabrifera dolabrifera) eats a TON of film algae, but won't touch anything else. I tried to get a Dolabella aricularia but couldn't find any in stock. I may try that again.

I had a few wisps of bryopsis but my pitho crabs ate all of it on like the 2nd day they were in the tank. Same for the other macroalgae in my display. The only issue in my tank is hair algae.

 

[fish_collector]

Try using ReefFlux (fluconazole), it helped rid my tank of GHA.

 

[slingfox]

I know exactly how you feel. I started my 125g tank for 100% Marco Rock. It looked pretty nice most of the time but I had many bouts with the uglies. For 9 months straight I dealt with a thick moss-like turf algae that mostly came out of the holes and crevices of the rockscape. I constantly had to scrape the algae but it kept coming back. The tide started to turn via coralline slowly outcompeting but at the 2-year anniversary of my tank I replaced my entire rockscape with ocean live rock.

I have had the new rockscape for 3 months and could not be happier. I do have some algae growing but you have to look really really close to find it.

I hope your algae situation improves. I believe it is possible to do a 100% dry rock tank well, but the risk of uglies is high. So much easier to at least use a mix of dry rock and live rock. If I had to start from stretch again I would cook any dry rock with ocean rock or sand for several months before adding any livestock or lights.

 

[Australian_Reef]

It’s not just Marco rock, I think it’s all dry rock. I had the same with caribsea. 12 mths of gha. Never had an issue with live rock on the 6 tanks I’d had before. After 14 mths and urchins it has now gone. The addition of aluminium based phosphate media (also removes silicates!) also helped I believe.

On my new tank I’ve again used caribsea rock but added live rock and seachem phosguard from day 1. And after 8 weeks I’ve still not added light to try and give the other organisms a head start. You may need smaller urchins to get in those holes!

 

[slingfox]

It’s not just Marco rock, I think it’s all dry rock. I had the same with caribsea. 12 mths of gha. Never had an issue with live rock on the 6 tanks I’d had before. After 14 mths and urchins it has now gone. The addition of aluminium based phosphate media (also removes silicates!) also helped I believe.

On my new tank I’ve again used caribsea rock but added live rock and seachem phosguard from day 1. And after 8 weeks I’ve still not added light to try and give the other organisms a head start. You may need smaller urchins to get in those holes!

Great plan with the new tank? Why kind of urchin have you found success with? I have two tuxedo urchins which are workhorses. I may get a different type if one of the current urchins ever passes away.

 

[CloudReefer]

It’s not just Marco rock, I think it’s all dry rock. I had the same with caribsea. 12 mths of gha. Never had an issue with live rock on the 6 tanks I’d had before. After 14 mths and urchins it has now gone. The addition of aluminium based phosphate media (also removes silicates!) also helped I believe.

On my new tank I’ve again used caribsea rock but added live rock and seachem phosguard from day 1. And after 8 weeks I’ve still not added light to try and give the other organisms a head start. You may need smaller urchins to get in those holes!

Some of the holes and cracks are 1mm or 2mm. Nothing gets in there to eat it so no matter how much I scrub it just comes back. I wouldn't even mind scrubbing to keep it at bay but it grows so dang fast.

I see my crabs eating it regularly but they can't eat it fast enough and I don't want to put 50-100 pitho and emerald crabs in my tank just to starve when it's gone and potentially start eating other things.

I might get a rabbitfish. bleh