Diatom algae ID (microscope)

alinpez · Dec 28, 2023

Hello guys,

I have a type of diatom that I cannot identify. Since I can't identify it, I don't know what triggers it or what it needs to survive.
From what I have observed, snails and Scopas fish do not even look at it.

I attach photos taken under the microscope, I think it must be some kind of Striatella.... but it looks different from those I have found, for example Striatella Unipunctata. It looks like one but it is not.

More importantly, how to eradicate it, any experience with it?

Thanks and regards!

Dan_P · Dec 28, 2023

alinpez said:
Hello guys,

I have a type of diatom that I cannot identify. Since I can't identify it, I don't know what triggers it or what it needs to survive.
From what I have observed, snails and Scopas fish do not even look at it.

I attach photos taken under the microscope, I think it must be some kind of Striatella.... but it looks different from those I have found, for example Striatella Unipunctata. It looks like one but it is not.

More importantly, how to eradicate it, any experience with it?

Thanks and regards!

How would one treat, for example, a Lithodesmium infestation differently from a Striatella infestation?

While diatoms have a need for silicate, we often forget that like any other a large population needs nitrate to go nuts (I assume phosphate is rarely limiting in an aquarium even though hobby kits cannot detect in the water).

taricha · Dec 28, 2023

agree with Dan, and I think these may be striatella anyway. (diatoms often have much more chloroplast in pictures in our tanks than pics of them in the ocean - maybe this is due to the tiny nutrient levels in the open ocean) But regardless, there aren't known genus level differences that'll tell you to do something different.
silicates, other nutrients, herbivores, surfance maturity etc. those seem to be the factors controlling diatom populations in our tanks.

vetteguy53081 · Dec 28, 2023

Seldom do i see striatella microscope images and nice and clear. Diatoms feed off silicates but also dissolved organic compounds, phosphates and nitrates. Tap water can contain silicates and is an easy way to get a bloom if you use it to mix salt or to replace water that evaporates. Filtering water through a RODI unit is best although you can still get diatoms when the cartridge that removes silicates becomes expired.
Diatoms are generally harmless and can be beaten once their food source expires. This type of diatom can return after beaten.
Some cleaners to help with control are Cerith snails, Nerite snails and Trochus snails and also Astraea snails

alinpez · Dec 31, 2023

Hey!

Thank you all for your answers.

I've been with marine aquariums for about 8 years, I'm used to diatoms and their needs but this one seems to be "special".

RODI's water has no silicates, neither does the aquarium. The no3 and po4 levels are low, 4 no3 and 0.02po4 respectively. Herbivores don't even look at it, I have many types of snails (trochus, strombus lentigunosus, luhanus, conus, astrea, nerite, turbos) but nobody seems to like it.

The aquarium where I have the diatom is fairly new but I have had the same problem in the main aquarium, where the plague began and there I have also low no3/po4/organics, a lot of coral and very stable... and it seems that it does not care to expand.

In the attached photo (main reef) below the Koi, is where the first sprout started. Then it has moved to the other aquarium I have.

Another little spot:

The aquarium is healthy and without excesses, I performed also an icp and everything was fine, nothing out of its ranges, that's why it's driving me crazy.

I'm going to try Vibrio at half dose in the secondary aquarium and I'll tell you the results, wish me luck...xD

Thanks again!