You let it happen. If you don't have your cleanup crew yet, you wait until you see green algae everywhere, then get a cleanup crew appropriate for your tank size.
Your rock needs to be mature and covered in algae. Until the rock is at least approaching maturity, you're going to have algae everywhere. Scrape the glass if you don't like the looks of it, and pull out any long tufts of hair algae by hand, as they won't be eaten by snails. Also, make sure your phosphate and nitrate aren't undetectable- photosynthetic organisms need those, and having too little of them will starve your beneficial algae out.
Assuming you're using RODI or distilled water, keep your nutrients somewhere reasonable, and stock an appropriate cleanup crew, the algae will all sort itself out. It might take a few months, though. That's the "ugly stage". Let it happen. Don't try to scrub the algae off the rocks, don't dose anything to kill the algae, don't try to starve it. Let the algae run amok until it sorts itself out.
If you started with dry rock, the ugly stage will last longer and be worse. You should try to get some rubble and other bits from an established tank to add additional biodiversity, and once there's lots of algae, adding a bottle of copepods could be a good idea.
Don't do anything all tanks goes through that stage & it will burn itself out. There's too much panic & reliance on throwing loads of different treatments in when in reality you just need to let tank sort itself out
Is it for sure Diatoms or could it be dinos? When I did a little 5 gal water change last night, the stuff came off the rock work easily with a syphon. thanks for all replys