50gal

So I've had this roughly 50 gallon tank for just over a month now. I've done 1 water change of about 50% about 2 weeks ago. And I'm now noticing this brown stuff on the front glass, there's some on the back glass too. I'm just wanna make sure it just algae, or is it something I should be worried...

Hi everyone, this is my first post here.    I have a 30Gal tropical tank and will be upgrading to a 50Gal corner tank in a few weeks. Super excited! I am looking for some advice about interesting and peaceful fish I could add. I was thinking of adding a few larger fish to mix with my smaller...