Is there such a thing as grass algae?

[naesco]

Originally Posted by asylumdown

In the 6 months since I set my 90 gallon reef up, one of the rocks, which started out looking like a cluster of tube skeletons, went from having brown slimy bits on it (how it came from the store) to being completely covered in what looks like the lushest, greenest lawn ever grown. We're talking millions of tiny strands of dark forest green algae that grows to a near uniform length of about 2 cm and is so soft and resilient that when I tried to push a frag plug into what had previously been a deep crevice in the rock structure it actually bounced out. it doesn't look like any hair algae I've ever seen, more like an actual plant or finely manicured golf course lawn. At first I was delighted because it was so pretty, but now little patches of it are starting to take root elsewhere in the tank, mostly in places that are slightly shadowed or don't get the full brunt of the metal halides. I don't know if it's something I should be concerned about, my tang nibbles at it on occasion but it's definitely not his preferred food. I run a phosphate scrubber and have never been able to get a color change on a nitrate or phosphate test, so I don't think it's a nutrient problem. Should I be worried? It really is quite pretty...

If your test kits are accurate and you might want to test for phosphates and nitrates at a LFS, in order to grow the algae you would have too much light IMO.
On the short term you can borrow a sea hare, acclimate her carefully and make sure you return her to the LFS or reefer afte the algae is mostly dealth with or she will starve.

[asylumdown]

thanks, I will look in to a sea hair and cut back an hours worth of lights. I had one back when I first set up the tank and the brown slime algae went out of control, but I had accidentally thrown out the mesh socks for my vortech mp10's (they looked just like the used filter sponge I was getting rid of) and it ended getting turned in to soup after a week. I made a new pair of socks for the vortechs last week when I discovered a really beautiful sea slug that had hitchhiked in to my tank (Sponge eating from what research I've done on it).

I'll take some pics when I get home tonight and post. I just checked back at some photos I took a month ago and that rock wasn't nearly as overgrown. I hadn't realized how fast it had gone!