Algae ID

[bmills15]

Just wanted to post a couple pictures of some algae I have been dealing with lately. Tank has been up for about 4 years now. I will list current tank parameters below. For the first few years I had a heck of a time with, what I would call fuzz, all over my rocks and was never able to get nitrate reading. Ever since I got rid of that, I have nitrate, but now I’ve been dealing with this. I have tested both the tank water and makeup water for silicate and always come up with nothing. To me, this looks like dynos, but I’m not sure.

Salinity - 1.025
Alk - 8.62
Calcium - 402
Nitrate - 4
Phos - 0.05

Thank you in advance for your input.

 

[Phycodurus]

i'm not seeing any bubbles, which i understand to be a classic sign for dinoflagellates. however, diatoms also seem unlikely if you've already confirmed zero silicates (but my gut says 'diatoms').

have you changed your salt brand recently?