Is this diatom?

SeeFu · Jan 1, 2020

I can't figure out if this is diatom or something else. it's not really hairy like algae, its more like skid marks. This started about 2-3 months after I turned on my lights. The rock was bleach soaked and its been in the tank for about 4 months now.

phosphate - 0.23
nitrate 0.75

King Turkey · Jan 1, 2020

If you are zero nitrate and phosphate I can see it being that. Classic new tank symptom turn lights off for a week and try again

taricha · Jan 1, 2020

Brand new tank. Carry on and ignore early phases.

SeeFu · Jan 28, 2020

how long should this stage last? It's been a month now.

King Turkey · Jan 29, 2020

SeeFu said:
how long should this stage last? It's been a month now.

Sorta depends hard to say

AZMSGT · Jan 29, 2020

Diatoms live off silicates, once the silicates are consumed they typically go away. However they can continue for a while living off nitrates and phosphates.

Yours is very minor at the moment.. it can get much worse.