Dinos or Diatoms?

[orangestorm]

My nitrates went from 1.3 one day to 0 the next. I started getting brown patches on the sand that can be sucked up. My phosphates have been high and I’ve been battling green hair algae. Phosphates were at 0.13 when my nitrates bottomed out.

The brown patches don’t have any bubbles and aren’t stringy or in a mat.

 

[55semireef]

Technically, the only definitive way to conclude what you have is to view the organism under a microscope. Dinoflagellates can broken down into 4 species that we typically deal with and sometimes it can be a bit more nuanced than just a visual to diagnose. That said, based off of your picture, it appears to be diatoms, which is the more ideal scenario. If you were to dose a silicate source, the diatoms would respond immediately.

However, even though these appear to be diatoms, dinoflagellates can be lurking as you have a perfect environment for them (bottomed out nitrates and elevated phosphates). Slowly increase your nitrates and stabilize your phosphates and ensure the flow in your tank has no dead spots.

Are you running any type of UV?

 

[orangestorm]

Technically, the only definitive way to conclude what you have is to view the organism under a microscope. Dinoflagellates can broken down into 4 species that we typically deal with and sometimes it can be a bit more nuanced than just a visual to diagnose. That said, based off of your picture, it appears to be diatoms, which is the more ideal scenario. If you were to dose a silicate source, the diatoms would respond immediately.

However, even though these appear to be diatoms, dinoflagellates can be lurking as you have a perfect environment for them (bottomed out nitrates and elevated phosphates). Slowly increase your nitrates and stabilize your phosphates and ensure the flow in your tank has no dead spots.

Are you running any type of UV?

Thank you so much!

I’m not running a UV at the moment. This is a 15 gallon HelloReef, so I’m not sure if a UV is overkill? What do you think?

 

[55semireef]

Thank you so much!

I’m not running a UV at the moment. This is a 15 gallon HelloReef, so I’m not sure if a UV is overkill? What do you think?

UV is usually optional rather than the main fix. Diatoms mostly live on surfaces so UV only helps with the portion that becomes suspended in the water column.

For a 15-gallon tank, something like a 7 watt UV at 60 GPH is a very reasonable setup. Honestly,
the bigger levers for diatoms are usually time/maturation, silicate availability, not overfeeding, reasonable light duration and manual removal. In a newer tank, diatoms often fade on their own once the available silicates are depleted.

All that said, a UV is good to have on the sideline in the event it is needed. I probably wouldn't buy a UV for just diatoms though. If this was truly Dinos, I'd highly recommend it.