Dino ID and management

[jts813]

2 year old 29 gallon tank. Have brown patches of sand under white light for the last year. Rocks and corals I don’t notice any issues. Recently had some fish death after first time using reef roids (separate recent post). I was thinking of some type of bacterial bloom/oxygen event and had me thinking about Dinos that I assumed I have. Finally found my kids microscope and got some pictures. Confirmed but not sure what type. I saw the pdf guide but couldn’t quite match up what species. My salifert nitrate reads between 10-25 color range. Phosphate not sure ordered hanna checker. But API phosphate test which I have trouble seeing color difference I think falls at 0.25. Doesn’t go lower than that. The brown sand goes away at night. In the past I tried like microbacter7 and green killing machine uv light but that was when I had a green hair algae issue a long time ago and I can’t recall if I had the Dino’s then. I think so? I try and siphon off top layer of sand but comes right back. Any advice on type of species and how to manage?

 

[jts813]

Sand photo

 

[MikeReefs]

Prorocentrum

 

[EnterName]

This looks like Prorocentrum to me, but I don't want to fully rule out coolia as @MikeReefs suggested. However, I think you can see the central pyrenoid (circle in its center) in your images which is a good indicator for the typical prorocentrum species found in reef tanks.

As the brown stains disappear at night it is likely that this species migrates into the water and therefore is vulnerable to UV sterilization. It might not fix the issue completely, but it's a first step. Getting reliable and accurate nutrient readings would be useful for determining further steps.

Just to show how different prorocentrum species can look, I have attached two images. Note that these are not bright-field microscopy images and therefore will look different from yours. The shape and some key characteristics such as the circle in the center are what is important here. The right speciment is a little bit dehydrated and therefore didn't fill its whole theca (shell/armor) anymore. You can find a few more images in my microscopy thread.

 

[MikeReefs]

This looks like Prorocentrum to me, but I don't want to fully rule out coolia as @MikeReefs suggested. However, I think you can see the central pyrenoid (circle in its center) in your images which is a good indicator for the typical prorocentrum species found in reef tanks.

As the brown stains disappear at night it is likely that this species migrates into the water and therefore is vulnerable to UV sterilization.

my first thought was coolia but the small indentation on the front looks more like Prorocentrum. Uv should help cus they release into the water column at night.

 

[Uncle99]

Goes away at night, back when lights on stuff?

If so, likely a variant in the golden class, the exact variant I have not idea, just how they behave,they multiply quickly and go into water column at night.

You nutrient level seems ok but make sure you go at least .1ppm phosphate available at all times.

The pest, well it’s a numbers game.

Anything that reduces their numbers while we keep conditions that favour the good guys.

Reduce numbers:
Replace filter just before lights on.
UV when lights off
Light vacum of sand surface when lights on, through a filter sock, return water.

Correct any chemistry (if required).
Maintain all parameters both the level and not fluxing.

Feed bacteria, just a splash daily.

Feed phytoplankton, again just a splash weekly.

There will a tipping point whereas the good bacteria and algae we want in our system, just overtake the real estate from the pest stuff. It’s these good friends that keep rocks clean and sand white.

Once gone, they will not return unless the environment changes, or becomes unstable in terms of chemistry.

Good luck. Be Persistent! You’ll win.

 

[CHSUB]

Don’t need Id or any special anything, the myth of dinoflagellates have exploded here to some super organism that can survive all other marine life. It is very simple, control detritus and inorganic nutrients by keeping your aquarium clean. Dinoflagellate are in every aquarium and ocean habitat, part of the food chain. Your nutrients are to high start by reducing them, it is common sense not marine biology.