what is this and what eats it?

[trottman]

I think i may have gotten this from the coral that i brought back from Mexico. my tank was fine until then. any clue to what it is? or what eats it? it was really out of hand and hairy, until i cut it down and brushed a lot of it off. it is rather strong. here are some pictures of it after i have manually removed as much of it as piossible.

i cannot get a tang, so that wont work.

nitrates - 0
nitrites - 0
ammonia - 0
ph - 8.3
sg - 1.028
i use ro water, my tds is 2 right now but is normally 0. i use coralife salt. all of my corals look great, sps are growing fast and are colorful. so i doubt that the phosphate lvl is very high. any clues?

 

[geoxman]

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1282165

 

[JB23]

Do you utilize RO water, or RO/DI water?
Jerry

 

[piercho]

Its usually called "red-wire alga". Its a red algae and usually "identified" as genus Gelidium or Gelidiopsis. Its physically pretty tough, tearing like thread when pulled off the rock. Its a common algae and will appear in well managed tanks with low nutrient levels. IME Siganus lo (foxface rabbitfish) and Acanthurus japonica (powder brown tang) both tear up this algae and other stranded red algae, which does you no good since you don't want a tang. Diadema urchins (long spine) will graze it. Tuxedo urchins are weak grazers of this type algae IME, but can assist to keep it from spreading. Tuxedos stay fairly small unlike the Diademas which get huge. I'm not aware of any snail or blenny capable of tackling this algae. I doubt lettuce sea slugs would do anything to it. Dwarf sea hares (Aplysia) - don't know. Removing the rock from the tank and wire brushing the algae off of the rock will set it back for a while.