Need help identifying algae

alyee5 · Apr 23, 2017

I have a similar looking "algae" in my tank...mostly on sand and now on rock...gets less prominent when lights go out...I did get a microscope and it looks like this...

I got some feedback saying they were diatoms, but not sure where the silicate source is coming from if they are diatoms ...I use the BRS 5 stage RODI unit...it reads 0 TDS

saltyfilmfolks · Apr 23, 2017

Ruckus16 said:
I have excellent flow. Two rw4s, koralia nano plus my return. I'm sure I have spots that settle detritus but nothing noticeable. This stuff has pretty much completely covered my sand.
No vacuum. I really dislike disturbing my sand beds

hmm. so it everywhere. could be silicates creeping in as the filters age?? Im just guessing build up.

Im a if its shallow, vacuum. if you don't want to disturb it, go dsb. everything goes down and theres IMO generally not enough microfaune or bacteria to process it in a 1/4 in o sand. but that's just me. I wouldn't leave that there.

saltyfilmfolks · Apr 23, 2017

alyee5 said:
I have a similar looking "algae" in my tank...mostly on sand and now on rock...gets less prominent when lights go out...I did get a microscope and it looks like this...

I got some feedback saying they were diatoms, but not sure where the silicate source is coming from if they are diatoms ...I use the BRS 5 stage RODI unit...it reads 0 TDS

diatoms are one of THE most common organisms on the planet. new rock and sand dissolves a bit in seawater (thus new tanks) so it builds up a concentration until they and the rest of the organisms eat what's available.. thats generally why they fade.

blizzardscout2 · Apr 24, 2017

If you don't run a DSB you should vacuum your sand. A year or 2 from now you will have trouble due to the detritus build up that never fully is broken down. Higher nitrates and phosphates will follow.

That definitely looks like diatoms. Your system is still very young and they will go away on their own eventually with good maintenance.

Hans-Werner · Apr 25, 2017

Ruckus16 said:
It's not cyano.

How do you know? I know cyanos you would never guess it´s a cyano like Lyngbya or Schizothrix. In my eyes it is a cyano or a mix of cyanos and diatoms.
For a definite indentification you need a microscope but I´m quite sure it is a mix of cyanos and diatoms. Filamentous cyanos give this filamentous structure.
I am sure it´s not dinos since dinos are not filamentous but slimy.

Ruckus16 · Apr 25, 2017

Ok. I will have a microscope Friday. What is the best way to collect a sample for a slide?
Is it fair to say diatoms mainly feed on silicate? I have not changes or added anything in my tank. My RODI maintenance is very good and I clean my mixing station and buckeye regularly. Where else could the silicate be coming from?

Ruckus16 · Apr 25, 2017

Just some more random info on my system.
Two small clowns
Six line
Gramma
Tailspot Benny

Fish are fed once flakes once a day by autofeeder
I spot feed my nems and coral once every two weeks. (Travel for work and that's what my schedule allows)
Reefbreeders photon v2 using their 12 hour day program. 25% max.
My skimmer is crappy but I have a new icecap arriving Friday.
No refugium
No media except carbon

Hans-Werner · Apr 25, 2017

The usual procedure ist to take a sample of the algae with a pipette, put a few (2 or 3) drops on a slide, cover it with a cover slip and put it under the microsope. Start with the lowest magnification of the microscope. Oscillatoria (cyanobacteria) will appear as quite thick long filaments while diatoms are needle shaped to elliptic and may look like a tiny boat.
Diatoms grow with silicate. Some silicate passes the RO, some silicate may come from the salt and some silicate may come from the rocks or filter materials like carbon.