Dinos, diatoms or something else

[Dubs83]

I've gotten this awful brown growth on my sand bed and now starting to move into my live rock and I'm not sure if this is dinos, diatoms or something else altogether.

About my tank, it's a 125 gallon (150g total)
And is about 2 months old

Temp 78
Ph-8.25 to 8.3
Ammonia 0
Nitrite 0
Nitrate 2.0
PO4 .02
Alk 8.3
Calcium 445
Mg 1280

I do two daily water changes of 4 gallons (8 gallons per day)

Can someone please calm my nerves a bit as I've read way too many restart threads where Dinos were the leading cause.

Thanks!

 

[nemo1017]

New tank? Most likely Diatoms eating off silicates from the sand. They'll go away on their own. If it's Dinos then it'll usually look like strings with bubbles. But it looks like just diatoms to me.

 

[aquaman30k]

+1 for diatoms. It will die down.

 

[Dubs83]

New tank? Most likely Diatoms eating off silicates from the sand. They'll go away on their own. If it's Dinos then it'll usually look like strings with bubbles. But it looks like just diatoms to me.

Thank goodness! I couldn't sleep last night because of everything I was readying about dinos!