Dark Maroon Velvet Algae?

[Toddww1]

this patch grows in every day in the same place on the same rock. never spreads. weird thing is, every night I shut the lights off and go to bed, only to wake up to a clean rock? no idea what this algae is, let alone what is either eating it or why it has this strange cycle. when i get home from work, there is the velvet patch again with small bubble algae that is clear instead of green growing on top. any ideas?

 

[cosmo]

sounds and kinda looks like cyano. certain snails/crabs will eat it. Kinda weird that it comes and goes that quick though.

 

[Sniperhank]

Has to be cyano. Prob comes and goes quickly from a quick spike in nutrients and it starves itself out i'd guess...

 

[Toddww1]

here is a pic this morning, 12 hrs later. gone. just little brown sand left. I do have 2 camel shrimp and a red spotted blenny that come out at night. I get tje water tested weekly and is always good. any suggestions? is it bad to leave lights off for a day? how long can u go without feeding to get nutrients down? my tank is 6 months old, no water changes yet, when is a good time and how much?

 

[Toddww1]

here is the pic.

 

[Sniperhank]

How old is the tank? Id say that the brown is diatoms, but a picture of it would be helpful. Just want to make sure that it isnt dinos and you are having some "red tide" going on in there.
How long are your lights on? With a nem and corals, you cant black out the tank but you can cut down the length they are on. 8 hrs should do for length they are on.
In terms of feeding, what do you feed and how much? Flakes contain excess nutrients and if you feed frozen food not thawing/rinsing them also puts excess nutrients into the tank.

 

[Toddww1]

here is the pic. 6 months old. frozen brine mix i melt in tank water and feed with a baster once maybe 2 times a week. very few pellets for my 2 clowns daily, not more than they can eat in a min. also phytoplankton 2 times a week for corals. been using teaspoon of fuel once a week as well. lights were bought 10 hrs a day, both blue and white T5. now tryin for 6-7 to help.

 

[Toddww1]

so i went to LFS and got an emerald crab and a turbo snail to see if that helps. also did a 5 gal water change.