Can I get an ID Please

[TheDon]

Been battling LCA and I was using the UV sweeper on sand for a while but haven’t used it since 12th September. Started my 10% water changes up again on 17th September on my reefer 250 and was cleaning top of sand, this was holding back the brown patches. Also dosing Tropic Marin Nitribiotic weekly, most of my slides I’ve looked at have been a lot of detritus and what look like diatoms. I’ve had a few cells that look like dinoflagellates but they haven’t been moving on slides!

Well today I found some that are moving! Am I still in the grips of LCA? If yes what do I do next!

• Do I continue with UV sand sweeping or do I just use the waterglass I’ve bought.

• Do I stop water changes?

 

[TheDon]

Another video, I do have quite a lot of the golden shards on slides.

 

[EnterName]

Sorry, I didn't see your post earlier.

That's Amphidinium (or Testudodinium but the community is treating it as Amphidinium anyways). The epicone (the "beak" of the typical Amphidinium species we frequently see in reef tanks) is less pronounced in your particular strain, but that's not too unusual. Depending on the focus of your scope, but also environmental factors, and the actual species/strain morphological features can vary quite a lot. Amphidinium also doesn't have a theca (armor) so the cell can change its shape significantly.

Light microscopy isn't really enough for a proper identification, but species like Amphidinium mootonorum (third row, image 1, and 2 or G & H) have a much less obvious epicone, so it's just a less common morphotype. Post #3 in my microscopy thread show how diverse the morphology of Amphidinium (and look-alikes) really is.

If you just found a few cells that's nothing to worry about. Dinoflagellates are part of the natural food chain and just as diatoms they will be always present in your tank somewhere. If you actually see them causing discoloration of the substrate or so, then it might be time to get active again.