Cyanobacteria or something else?

[duesmortem]

Hey y'all! I have had this 40 gallon tank set up for a few years now. I have been having this brown hair-like slime growing on my glass after every single water change for the past 2-3 years. I think that it is cyanobacteria but I am not 100% sure.

The odd thing is that it seems to grow on the glass that is most exposed to the AI Prime light for the tank. The tank has pretty strong flow in this region so I am also surprised that this grows here.

I am planning on checking my parameters this weekend. I will post that data here once it is collected. Please let me know what you think or ask questions in the meantime!!!

 

[Gman83]

You said it hair like slime? Do you see any bubbles that look like they are trapped in the slime?

 

[duesmortem]

You said it hair like slime? Do you see any bubbles that look like they are trapped in the slime?

No bubbles at all. It just grows in small patches that eventually connect and cover the glass

 

[duesmortem]

I finally was able to test my parameters and they are as follows:

Nitrate - 4.1 ppm
Phosphate - 0.20 ppm
Calcium - 437 ppm
Magnesium - 1321 ppm

I am still waiting on the reagent for my alkalinity colorimeter.

I am assuming this keeps happening due to high levels of phosphate in the tank. Does anyo e have experience using Ferric Oxide (GFO) to gradually reduce phosphate levels?

 

[EnterName]

Dinos and/or diatoms. They don't mind rough flow and will simply grow/attach accordingly. A microscope would help.

Sometimes green hair algae is covered in diatoms making it appear brown but it doesn't look like that. The stringy bits are probably the mucus dinos produce. Bubbles are most likely not present because the flow carries the oxygen away before it accumulates.

GFO works great for reducing phosphate. Just stick to the instructions to not accidentally overdose.

 

[duesmortem]

Dinos and/or diatoms. They don't mind rough flow and will simply grow/attach accordingly. A microscope would help.

Sometimes green hair algae is covered in diatoms making it appear brown but it doesn't look like that. The stringy bits are probably the mucus dinos produce. Bubbles are most likely not present because the flow carries the oxygen away before it accumulates.

GFO works great for reducing phosphate. Just stick to the instructions to not accidentally overdose.

Thank you so much for the response! I can bring a sample to my job on Monday where I have access to a microscope. I will also try to grab some GFO from my LFS this weekend and see how the phosphate levels change. If I reduce the levels to below 0.08 ppm then would this issue on the glass persist?

 

[EnterName]

I can bring a sample to my job on Monday where I have access to a microscope.

Perfect! A magnification of 400x (10x eye piece, 40x objective) works very well for identifying dinoflagellates in my experience.

If I reduce the levels to below 0.08 ppm then would this issue on the glass persist?

I can't promise you that this alone will fix the issue, but 0.08ppm is a decent target in my opinion and should support a healthy reef tank very well

To collect the sample I would use an algae scraper and a pipette. You can use the pipette to catch what the algae scraper should remove from the glass quite easily. I would do this just before driving to work so the sample is "fresh".

 

[duesmortem]

I can bring a sample to my job on Monday where I have access to a microscope.

Perfect! A magnification of 400x (10x eye piece, 40x objective) works very well for identifying dinoflagellates in my experience.

If I reduce the levels to below 0.08 ppm then would this issue on the glass persist?

I can't promise you that this alone will fix the issue, but 0.08ppm is a decent target in my opinion and should support a healthy reef tank very well

To collect the sample I would use an algae scraper and a pipette. You can use the pipette to catch what the algae scraper should remove from the glass quite easily. I would do this just before driving to work so the sample is "fresh".

I will post the microscope pictures at some point on Monday! I was planning on cleaning the tank today, but I will wait so I have a sample to use on Monday. Thank you!