Diatoms 9 days in?

[powerfulalex]

Here's some pictures of the diatoms in my tank. I'm using the fluval evo 13.5, 13 pounds of live rock and carib sea aragonite. Is it okay that it's happening this early into the cycle? I added my live rock about 9 days ago, there's some hitchhikers that came with it (2 emerald crabs, another crab that looks similar but it's pale/red, and a bristle worm!). My LFS also told me to add a chromis, so she's been in there for about 5 days. I haven't tested my water yet, my LFS told me they'd do my water testing for free, for convenience I may buy that API water testing kit to do it myself.

Could the issue be water flow? I have the aqueon 500 powerhead but it's pointing upwards towards the surface because I had it pointing at the other side of the tank and I thought the water might be too strong for the fish? I've also never had a fish tank before so I could be completely wrong!

Also, would I be able to add another 10 pounds of live rock to my tank even though it's cycling? I would like the arch to be much higher up, so I'm thinking of adding two more larger rocks to the bottom.

 

[Reefing Madness]

Totally normal for diatoms, no worries. Your LFS should be shot, you should not be adding fish to any tank that is cycling.
Yes, you can add more rock to the cycling tank, as long as you don't add it towards the end of the cycle. Or you could add Cured Live Rock anytime.
At this point if your LFS told you to add fish, I'd not trust him to tell me my water conditions were good, he might tell you to buy this or that when you don't need anything.
Live Rock will cycling your tank for you. Thats basically all you need. You could add a frozen shrimp to the water (throw it in a fish net, laying in the water) and that will bring up the ammonia level for the bacteria growing in the rock.