Brown Coating on Live Rock (Not Diatom)

[MasonK24]

A little background on the rock,

The rock was bought second hand with a tank and the owner barely did water changes and used tap water. It was completely covered in GHA when i aquired it and i doctored it back to health. After a long time with high nutrients and trying carbon dosing I got a bad case of dinos and ended up removing all live stock. its been around a month with no lights and the dinos have seem to go away unless this coating is indeed dinoflagellates. if that being the case, id be very surprised if it is still alive after a month of complete darkness. i would like to use this rock again without killing the BB but im worried that this brown stuff could be bad. thanks

 

[GoVols]

FWIW:
Carbon dosing can strip nutrients out off the water column. Then your BB will die off.
Then it opens the door for dino's to take a hold.

You have to out compete dino's to not firing up, and dino's love ULN'S reefs. Water changes will make matters worse when dino's kick in.

To me, a black out is a cover up to a bigger root issue. It will just come back, if the issue is not resolved.

 

[MasonK24]

FWIW:
Carbon dosing can strip nutrients out off the water column. Then your BB will die off.
Then it opens the door for dino's to take a hold.

You have to out compete dino's to not firing up, and dino's love ULN'S reefs. Water changes will make matters worse when dino's kick in.

To me, a black out is a cover up to a bigger root issue. It will just come back, if the issue is not resolved.

thats not really what im after. i dont really care about the dinos at this point. this tank has no livestock. i just want to know what the brown coating on the rock is. thats the reason i posted this

 

[MasonK24]

Description of this brown coating.

-not really slimy
-is more of a dust
-will NOT blow off rock with a turkey baster
-does not have bubbles
-not stringy
-will come off rock when scrubbed very hard with a tooth brush
-hasnt seem to spread in months
-is not photosynthetic

 

[Foothill Corals]

IME Vibrant will get rid of it.

 

[MasonK24]

here is a microscopic view of it i took a picture of. can anyone ID?

 

[Jenksreef]

I have the same stuff in my tank. I have no idea what it is. Did you ever figure out what it was? Also, what ended up happening to it over the long haul?

 

[MasonK24]

I have the same stuff in my tank. I have no idea what it is. Did you ever figure out what it was? Also, what ended up happening to it over the long haul?

turned out it was the Amphidinium strain of dinoflagellates. this was over a year ago in my old tank that has long been taken down. i upgraded from that 15 gallon to a 75 gallon and i am still dealing with it. its an extremely difficult and long battle. i did not want to get rid of my dino infected corals so i transferred them to the new tank and the dino tagged along with them in their tissue. (dino cant be killed with a dip) my strain hasnt caused me any harm besides cosmetic. i cant keep a nice white sand bed and it dusts the glass very fast. the one thing that did keep it down effectively was silicate dosing. there are many helpful threads on Reef2Reef on dealing with this monster of an organism. i would suggest doing some research. Goodluck!