I know about the “ugly” stage of cycling but this is ridiculous.

[Nate Chalk]

That looks like diatoms

 

[Frostblitz20]

What do you have for CUC?

I would get something to stir the sand like a conch snail fighter or strawberry.

urchins are great for control just can’t over populate.

 

[N1gh7m4r3]

My 40g got T5 lights last month after being up a year without lights. I knew I’d get algae and diatoms but not this much. Parameters are fine. Nitrates slightly above 0 and Phosphates 0. When is this going to end??? The hair algae on the rocks is light brown and some on the sand is green. Tank inhabitants are all fine but boy is the tank ugly! Any thoughts?

I actually think those last two pictures look kind of cool.

 

[zuri]

man I miss saltyfilmfolks good guy.... this is old thread

 

[vetteguy53081]

Its Chrysophytes and will need to be scrubbed off by hand outside of tank along with Hydrogen Peroxide. Additionally, check soluble silicates as some Chrysophytes use silica to form their structures which may derive from DI resin in the RO unit. Reduce white light intensity also for a few days/ After cleaning an urchin such as pin cushion will be helpful