GHA/Turf because of leaching rocks

[Garf]

My scrubber is my only piece of equipment for nutrient control/export, and my only form of filtration aside from live rock and sand. I don’t do water changes. So actually the scrubber is doing pretty much…everything

Ive been monitororing algal succession in my tank for such an occasion, with the only downward pressure on algal growth that I’m aware being herbivory/time. Now, if I had danced up and down with a silly hat on screaming some ancient voodoo, I could quite legitimately believe that all the silliness was the reason behind the magic (no algae) result; thus;
Edit, pic added 15 Feb 24;

 

[DanConnor]

Just put in 50 turbo snails.

 

[Mr. Mojo Rising]

What is the nitrate level? How often do you do water changes? Do you scrub the algae with a toothbrush couple of times per week? Do you have a skimmer? Running a wet skimmer does help. Frequent small feedings instead of large infrequent feedings , I've become convinced that rotting food is a primary fuel source for algae.

I don't believe the rocks are leaching phosphate. I've had rocks leaching phosphate before, my phosphate was always .5 even with algae, i had to change the gfo every 1 or 2 weeks for 2 years.

You waited 2 years to add corals, but adding corals is the way to introduce more bacteria and biodiversity into the tank. More corals also helps to shade the rock so algae can't grow.

No need to replace your rock, just get a piece of rubble from a tank with live rock, all the bacteria in that tank will be in your tank, no need to complete rock swap.

 

[ScubaSkeets]

I have come to the conclusion that I think my two year battle with what is either gha or turf algae is because of leaching phosphates from the rocks. When I started the tank I used brand new macro rock and I have heard that it can leach phosphates that lead to algae. I have no algae anywhere but the rocks and zero phosphates in the water column. If I were to take out these rocks and replace them with dry or wet live rock could this be a solution where the algae would not return?

My tank was overrun with algae similar to yours. Zero P and N.
None of the "traditional" methods / suggestions worked for me.
Here is what I did:
During a water change (in September 2023, I think) I removed about half of my rocks (the ones that didn't have coral/anenome attached). I took them outside and sprayed hydrogen peroxide on them, waited a few seconds, and then pressure washed them. I then soaked them in old water change water for a few minutes, and returned them to the tank.

Around the same time, I put together a DIY algae scrubber and put it in my sump.
After some time, the hairy algae that was on the rocks that I could not pressure wash had gone away. And none of the long hairy algae has returned. And my N is 5.0-10.0 and P is 0.03-0.08.
I did nothing else to the tank. No change in lighting, no adding a CUC, no chemicals, nothing.

Sure, some folks are going to doubt my success by looking at my ugly white only pics, or zoom in on a pic and point out "aha!!! I still see alage in your tank" but I know what I had with my algae issues before, and I know what I'm looking at now

 

[Dan_P]

I have come to the conclusion that I think my two year battle with what is either gha or turf algae is because of leaching phosphates from the rocks. When I started the tank I used brand new macro rock and I have heard that it can leach phosphates that lead to algae. I have no algae anywhere but the rocks and zero phosphates in the water column. If I were to take out these rocks and replace them with dry or wet live rock could this be a solution where the algae would not return?

Another conclusion that can be drawn from these photos is that the system is trace element depleted. No coralline covered rocks can be the reason for all the algae. Another hint that the system is starved of trace elements is lack of sponge and tiny fan worm growth. Also, the clean up crew is not eating the algae.

 

[Bruce Burnett]

Never had hair algae problem with Marco Rock. Started with lots of snails and a foxface. Do have a hard red algae which won't brush off but it is not in shaded areas. I feed heavy, seldom check phosphates or nitrates. If I see algae growing I just increase my ATS run time. I run all for reef, skimmer, roller filter and ats. I do not do frequent water changes around 20 gallons about every 6 months when I clean pumps. Tank is 3 years old and sand is still white. I believe maintain essentials but keep hand off as much as possible.

 

[FunnierThanUThink]

I find growing fast growing macro algae, mainly grape caulerpa, and a large cleanup crew does best. Large like 1 small snail and 1 small hermit crab per gallon. I am constantly dosing to keep nitrate and phosphate up. I grow the caulerpa with a rest during the brightest 2-4hrs to keep ph stable.

 

[Hans-Werner]

It reads zero but that is because it is all tied up in the algae.

I think it is the reason and you are confusing cause and effect. With zero phosphate in the water nothing else will grow except the hair algae on the rocks that may contain some phosphate still.

Maybe the hair algae have acces to phosphate in deeper layers of the rock where the leaching process had little effect. You conclusion may be come close to reality if the hair algae prevent the phosphate from leaching into the water. Nevertheless the zero phosphate in the water in my eyes is the cause.

On dead rock the chance is much higher that hair algae will grow, well, because they are dead and nothing else is colonizing the surface. Also coralline algae have to be introduced in some way to start growing and displace the hair algae. Maybe you know some reefer or shop that can give you some fresh coralline algae. Crush them into little pieces (i. e. in a mortar) keeping them wet and "seed" the tank with the particles if you don't want to replace the dead rocks with live rock.

 

[TeeJay87]

Ive been monitororing algal succession in my tank for such an occasion, with the only downward pressure on algal growth that I’m aware being herbivory/time. Now, if I had danced up and down with a silly hat on screaming some ancient voodoo, I could quite legitimately believe that all the silliness was the reason behind the magic (no algae) result; thus;

Just putting this out there for others who may come upon this thread dealing with GHA problems. 1) Your green algae situation is nothing like the OP’s GHA situation. 2) Looks like you’ve got some corals in there and tons of coralline algae, which also put downward pressure on the green algae for nutrients and space.

 

[Garf]

Just putting this out there for others who may come upon this thread dealing with GHA problems. 1) Your green algae situation is nothing like the OP’s GHA situation. 2) Looks like you’ve got some corals in there and tons of coralline algae, which also put downward pressure on the green algae for nutrients and space.

I agree with some of that, not the nutrients bit though, certainly not in my tank. To put things into context, that post was in reply to folks who keep throwing algae scrubbers around like they are a magic cure, they are not. I'm actually glad you found that post, I had lost it and have an updated picture to add, it's not on this device though, so later.