Brown algea ID, with micropcope photos, diatoms?

[Shorebreak]

I have seen a sudden increase of this brown algea on rock, sand and glass. I purchased a microscope to try to identify what it is. I have had undetectable phosphate and nitrate, but have since turned skimmer off and dosed brightwell nitrate and phosphate. The algea has gotten worse sense then. This is at 200X and 500X. Its actually hard to get a sample. It does not come off easy and does not disappear with lights out.

The tank is a few months old with new argonite sand, but old live rock 5 years plus.

I have a 6 stage RO with zero TDS reading, fairly new TDS sensor and media.

 

[Idoc]

Primarily diatoms in those pics...one pic shows one cell that may be a dino, but this definitey doesn't look like a dino infestation.

 

[Shorebreak]

Primarily diatoms in those pics...one pic shows one cell that may be a dino, but this definitey doesn't look like a dino infestation.

Thanks for the response. I thought I may have seen a few dino shaped forms. They are more circular correct? I did see a few like that, but most were triangular. With a quick search, I only found diatoms shapped like the triangles. Are dinos generally the same size as the triangles in the photos at 500x. There appears to be much smaller round shapes, but I can't get zoomed in enough, the microscope isn't the greatest, it has 2000x, but I can't get it to focus at that power.

 

[Idoc]

Thanks for the response. I thought I may have seen a few dino shaped forms. They are more circular correct? I did see a few like that, but most were triangular. With a quick search, I only found diatoms shapped like the triangles. Are dinos generally the same size as the triangles in the photos at 500x. There appears to be much smaller round shapes, but I can't get zoomed in enough, the microscope isn't the greatest, it has 2000x, but I can't get it to focus at that power.

Some dinos are less than 5 microns, some much larger...they come in all sizes. Those small circles look more like possible film algae or other types of algae. Chrysophytes are small like that...without movement...but those have a golden coloration typically. The really small dinos, small cell amphidinium dinos, move around constantly like little racers shooting around. I don't think you have any concerns right now with dinos. But you need to keep those nutrients up so the dinos don't get the upper hand.

 

[Shorebreak]

Thanks for taking a look, tested today and I am finally seeing some nitrates, 2.5 PPM, still no phosphate, time to up the dose..

The algae seems to be about the same, not any worse and the corals all look fine, except for one small SPS frag, the algae is growing on it a little.

 

[Shorebreak]

Some dinos are less than 5 microns, some much larger...they come in all sizes. Those small circles look more like possible film algae or other types of algae. Chrysophytes are small like that...without movement...but those have a golden coloration typically. The really small dinos, small cell amphidinium dinos, move around constantly like little racers shooting around. I don't think you have any concerns right now with dinos. But you need to keep those nutrients up so the dinos don't get the upper hand.

So the diatoms seemed to be on the way out, but I have a bit of this stuff on the sand only. It's heavy in small areas. Looks slimy brown. Any ideas what this is?

 

[dwest]

I believe I still see diatoms.

 

[saltyhog]

So the diatoms seemed to be on the way out, but I have a bit of this stuff on the sand only. It's heavy in small areas. Looks slimy brown. Any ideas what this is?

Those are a different species of diatom from the first picture. I have the ones in the first picture on my power heads and occasionally the rock. The ones in the second picture are dominant on my sand.

 

[Idoc]

So the diatoms seemed to be on the way out, but I have a bit of this stuff on the sand only. It's heavy in small areas. Looks slimy brown. Any ideas what this is?

This are also diatoms... just different type.

 

[Shorebreak]

Those are a different species of diatom from the first picture. I have the ones in the first picture on my power heads and occasionally the rock. The ones in the second picture are dominant on my sand.

This are also diatoms... just different type.

Thank you for the ID. I see the same thing. The larger triangles were predominantly on the back glass and powerheads, they look like brown fuzz. The smaller needles look like brown slime and are only on the sand.

 

[Shorebreak]

Thank you all, interesting as the rock is all old, but the sand is new. I'm guessing the silica is coming from this as I have mostly new media in my water station and 2 different tds meters are reading 0.