Purple hair algae?

[Gatling]

Hi all,
I am not sure why I have some purple algae (and some brown stuff too) growing. My tank is 4 & 1/2 months old and I don't have any fish since I am a student and I haven't had time to deal with that yet. I have 5 Astrea snails, 2 Nassarius, and an emerald crab. My tank is all cycled and I was algae free for a month and then BAM. A purple overdose everywhere! At first I was like "This is pretty" but now its just getting ugly. My Nitrates/Nitrites are at 0 as well. The sand bed is also so messy. What should I do? Just let it be for a few months? I do often take a tooth brush and clean the rocks every week or so. I plan on picking some fish up after the new year!

(Please ignore my aquascape/rockwork, I didn't have the prettiest rocks to build with haha )

 

[Scrubber_steve]

thats cyanobacteria and diatoms on the sides

 

[lapin]

I would say to guess the reasons you have cyano are:
you have nothing else to use up any nutrients that are in the water
you have an imbalance of what nutrients you have
there is nothing to block the light that cyano needs to grow
cyano is bacteria and is everywhere and pretty easy to grow

 

[Scrubber_steve]

what is that you're using for gravel, & how deep is it?

 

[Gatling]

what is that you're using for gravel, & how deep is it?

Im using the caribsea black hawaiian sand and it's roughly an inch deep. I have a gravel vacuum but the day after I clean my sand bed, the algae grows back. I mean it could be much worse but it is annoying. I also turn on the blue light to help stop any growth.

 

[Gatling]

I would say to guess the reasons you have cyano are:
you have nothing else to use up any nutrients that are in the water
you have an imbalance of what nutrients you have
there is nothing to block the light that cyano needs to grow
cyano is bacteria and is everywhere and pretty easy to grow

What do you mean I have nothing else to use up the nutrients?