Red velvet substance on rock?

[kenmx10]

One of my pieces of live rock is growing a red carpet like substance all over it. Almost covering the whole rock. All other rocks have none. Im using a ro/di filter and my water test good for ph, nitrate, nitrite , and ammonia and phosphate. It is dark red and looks fuzzy like velvet. Any ideas?

 

[Kurt_Nelson]

Does it brush off fairly easy and is kinda slimy? If so, then sounds like cyanobacteria. Bad thing. Too many nutrients in the water. With a cyano problem, your water parameters will often test "perfect" because the cyano is eating the nutrients (nitrates, phosphates, etc) as fast as they go in the tank.

Best thing to do is siphon as much out as you can and figure out where the nutrients are coming from. If the rock is easily removed from the tank, then taking it out and scrubbing it in salt water would probably be best.

How big a tank, and what livestock? How often do you feed?

 

[kenmx10]

No. Its pretty hardy and soft feeling like velvet. It doesnt come apart. Its not cyano. Algae grows very slowly in the tank. I could get by cleaning every 2 to 3 weeks. Its a 60 tank. I have one damsel that gets fed 2 flakes every other day. One sea hair. I just added phos-guard to the filter last week. But with the ro/di filter ive been getting good water. My ph was at 7.7 so i added kents super buffer to bring it up. Thanks for you interest.

 

[apollothesun]

i know what your refering too. short and bushy. might want to add a cleaner crew of snails or a tang. my snails and yellow tang keep a check on mine.

 

[Shane and John]

I definatly agree with Apollo...we had some of the same things going on,after adding a small tang and a about 10 snails we never saw it again!!