Do you carbon dose at all?
The tank was started with all new Marco dry rock, and new sand. Only about 5 pounds of seed rock has been added to the tank, and it's from a clean, well established SPS system.
Ahhh, I see. It is due to the dry rocks. The rock is continuously leaching dead material. Those are type of biofilm bacteria and only time will get rid of it. As long as your parameter is in check, the bacteria is doing a good job to cure the rock.
That is very interesting. As Dong said, i've seen this form on dry rock (same description) but never to that extent. The fact that it isn't growing in shaded areas suggests that the light is somehow fueling it......lights out might be your best bet to see if you can get ahead of it. I would lights out and run carbon, GFO heavy for like 4 days. Then do a good water change after you go lights on to hopefully give it another knockout punch.
That is very interesting. As Dong said, i've seen this form on dry rock (same description) but never to that extent. The fact that it isn't growing in shaded areas suggests that the light is somehow fueling it......lights out might be your best bet to see if you can get ahead of it. I would lights out and run carbon, GFO heavy for like 4 days. Then do a good water change after you go lights on to hopefully give it another knockout punch.
+1There are many different species of dinoflagellate that can be different shades or brown, and this is what I am suspecting this is.
Is this something that should be expected with all dry rock? I'm curious because I just started my tank with about 28lbs of CaribSeas Dry Rock and 3.5lbs of live rock.