Algae/Dinoflagellates ID

[Ian_B]

A brown growth started appearing on my sand during the day. When the lights are out it goes away, and I’ve been having trouble with algae eating snails dying and being lethargic, so I’m afraid this is some type of dinoflagellate. Can anyone tell what type from the picture or video? They don’t seem to really move and just stay on the grains of sand.
Thanks

 

[Luckki]

For your video can you upload it to YouTube and post a link, for some reason the server does not like direct files. Is that image under magnification?

 

[Ian_B]

I can try to upload it to YouTube, but it’s pretty much the same view just showing whatever’s on the sand not moving. It is magnified, but I used a digital microscope and I can’t tell what the magnification is set at other than between 50x to 1000x

 

[Luckki]

I can try to upload it to YouTube, but it’s pretty much the same view just showing whatever’s on the sand not moving. It is magnified, but I used a digital microscope and I can’t tell what the magnification is set at other than between 50x to 1000x

It looks like it might be a mix but what might help is a picture of the tank too. To see the strands and mucus. My thoughts based on shape are Ostreopsis and Coolia as they will migrate into the water when the lights are off. They are toxic and slightly toxic respectively. How old is the tank and do you know the nitrate and phosphate levels?

 

[Ian_B]

There doesn’t seem to really be any strands that form, it’s mostly a mat that sticks to the sand.
Nitrate is about 10 and phosphate is about 0.02 but I’ve been dozing neophos and neonitro because I’ve dealt with dino's before and now I usually does nitrates and phosphates to keep them up.

The tank is about 2 years old, but I did move it in September and refilled it with new sand.