ID please - fast moving micro critters.

[The Life Aquatic]

Long story short, I took some "donor" sand home to seed my tank and help fight my dino fight but I decided to put it under my microscope first and I have no idea what I'm looking at. They are very small, like 1/5 or even /10 the size of prorocentrum dinoflagellates and move FAST.

To the naked eye the sand seems like it has diatoms but I've never seen diatoms that move like this. Doesn't mean it's not diatoms, just nothing I've seen first hand.

 

[The Life Aquatic]

Update: I'm actually now wondering if it's SCA! Likely not putting in my tank.

 

[krollins]

Update: I'm actually now wondering if it's SCA! Likely not putting in my tank.

I don't understand what SCA is. It could just be REALLY biodeverse sand

 

[The Life Aquatic]

I don't understand what SCA is. It could just be REALLY biodeverse sand

Small Cell Amphidum dinos. Hard to tell given they are so small (this was 400x) and move so quickly but I don't think the risk is worth it.