Brown / Red Algae in Sand and on Rocks

[Patrick Cox]

My tank is about 3 years old. ~150 gallons total water volume

In February, I decided I wanted to lower my nutrients so I added an Algae Turf Scrubber. Nutrients were as follows..

NO3: 32
PO4: 0.11

In May I added some new rock to the tank to create more hiding places for fish.

Now, over the past few months I have been battling either diatoms or dynos or maybe something else, not sure. Since then my nutrients are way down and I can't get rid of the bloom...

NO3: 4.8
PO4: 0.01

I added some corals and the algae is growing everywhere and killing them. (Sorry the pictures are not great.)

What should I be doing now?

Thanks.

 

[Gumbies R Us]

What kind of CUC do you have?
Almost resembles the dinos I had in my tank.

 

[SlothMartin]

I have a new tank and had similar growth and bought a microscope, turned out to be diatoms. i increased clean up crew and its pretty much cleared up. However the algae i had never killed anything. if its killing things might point to dinos?. if the dinos are toxic i have heard they can kill snails. how are your snails doing?
maybe consider taking the algae scrubber offline to prevent nuts from bottoming out?

i have an ATS coming this week so this is freaking me out a little bit :)

edit: forgot to ask, does the algae change during night/day cycle? my diatoms did not. dinos can go into the water during the night so if you see the sand clear up after lights out, and then return when the lights turn on, could be another indicator, but microscope best way to be sure

 

[Patrick Cox]

I actually don't have much CUC. I have a few Nasaurius snails but not many left. I guess that is what I need. what is best for this? snails or crabs or both? thanks

 

[Fish Fan]

If it's actually reddish in color, it may well be cyanobacteria. It could also be that you have a combination of cyano and diatoms or dinoflagellates algae.

When you say it's growing over the corals and hurting them, that sounds like Dino's to me. I had them wipe out a whole tank of frags in a very short time when I was out of town for I think four or five days is all it took. I came home, and the whole tank was brown and grown over with Dino's.

If you do have Dino's, here a great guide to dealing with them from the late Miami Reef:
https://www.reef2reef.com/threads/beating-dinoflagellates-a-complete-guide.1129648/

Here's some BRS videos on the other pests that may help:
https://www.bulkreefsupply.com/cont...6zxPEMXwEjhE_X4VJIIG_7zJs2Dk7QjhdohGZmf7okKY9




Good luck!

 

[Mr. Mojo Rising]

How is the flow in your tank? Especially since you mentioned you added some rocks which might have changed the flow patterns and created some dead flow spots... just an idea.

 

[RobertK]

Those photos look a lot like the dinoflagellate bloom I'm currently fighting in my tank.

Do you have access to a microscope? I think it is pretty much impossible to know exactly what you are dealing with without one. Even if it is dinos there are different types that can respond differently to treatments.

NO3 of 4.8 should be OK. PO4 of 0.01 might be an issue. Phosphate bottoming out has been associated with dino blooms. How are you checking N and P and are those readings consistent?

 

[Patrick Cox]

I use a Trident NP and test daily. Both have been trending down. And I recently calibrated it. I will look into the microscope. Thanks.

 

[Patrick Cox]

I think it is Dino. Thanks for video link above. Starting protocol...