Newbie algea problem/diatoms

[spikeyspud]

Hi everyone, basicly my tanks been running for about 3 months now so im aware its still very early on. Im looking at this browny stuff thats growing all over everything in my tank ive siphoned it off the rocks every week on the water change and siphoned areas of the sand weekly but it just comes back, it doesnt seem to be growing thicker or longer but it just covers everything and grows back relatively quick.
I thought i already had diatoms come and go but im wondering if what u had was something else and this is the diatom ugly phase or if its something else. I know its not much to go on im still learning so i want to identify what this is and if its just a waiting game wait it out or if i need to do something about it atleast have a direction to go in. Sorry for rambling on!
Also ive looked through the forums and i dont know if im looking for the wrong thing so i thought id just ask

 

[Rocks reef]

Do you happen to know what your nitrate and phosphate are?

 

[Gumbies R Us]

Do you have CUC in there?

 

[Fishy888]

It’s hard to tell, but do you see strings in it?