Is this algae?

[spacepops]

I recent medicated this tank for ick then this popped up

 

[King Fisher]

The last pic looks like diatoms/brown algae.

 

[spacepops]

Well that’s great I have it taking over my biocube and now my column tank as well smh. It’s all the same in the photos just really black on the other spots

 

[King Fisher]

I continue to have this problem in one of my tanks and it's been running for 2.5 years now. I don't over feed and it's not newly established which they say causes it. In fact, I never had this problem when it was newly established. I have two other tanks that don't have this problem and I treat them the same. The only thing I could figure was this particular tank is moderately planted and I use liquid fertilizer. Maybe it's the fertilizer?? I tried several things to combat it until I gave up and bought nerite snails. They keep it clean now.