What is this stuff? Good or bad???

[weld1jac]

Hope you all can help me out. I'm pretty new to the hobby and have been reading a lot. I recently purchased a 55 tank and all the equipment from a friend who was getting out of saltwater due to several upcoming moves. He gave me approximately 60 pounds of live rock which I currently have in a large container (it is all submerged with a light and a power head circulating the water). I noticed that some of the rock is partially covered with this purple/red slimy stuff. Algae? Sponge? I checked with my LFS and they suggested scrubbing it off. I thought that I'd check with you all to see if you could ID the stuff before I get rid of it. I don't want to set up the new tank with the live rock until I know if it's something that I should scrub off first. Thanks for any help you can offer!!!!

Sorry, this is the first time I've tried to attach a picture. Not sure I'm doing this right....here's a link to the photo I placed in my member gallery:

http://reefcentral.com/gallery/data/500/126485Stuff_on_live_rock.jpg

THANK YOU!!!!

[bertoni]

Hard to be sure from the picture. It might be an encrusting sponge. Can it be blown off the rock with a turkey baster? If so, the film is probably some sort of microbe, and that's very common as well. I would put a heater into the tub to get the temperature to 82 F or so.

[AIMFish]

The pic is pretty small, If it comes off easy and looks velvety it could be cyanobacter. Vacuum it off when doing a water change.

[weld1jac]

Sorry that the photo is so small!! When I attached it to the post it was originally refused because the image was over 50kb so I had to resize. I'm sure I've done something incorrectly....as I see other images posted that are decent sized. Anyway, the stuff doesn't seem to be easily blown off. I pinched a section off it...it will tear and it's kind of thick and underneath it's green and almost has a layered structure to it. I'd say it's about 1/4 inch or so at the thickest spot. It's soft and velvety feeling.

Thanks for the help!!

[bertoni]

I'd guess an encrusting sponge. If you don't like the looks, you can try to eradicate it. I'd probably ignore it. It won't hurt anything, although it might cover up some coralline algae that you think are nicer looking.

[weld1jac]

Thanks for the replies. I wish that I could find a picture out on the internet. I'm thinking that It probably is an encrusting sponge. It's actually not unattractive.....just don't want it taking over all of the live rock once the tank is set up. Could anyone tell me how it migrates from rock to rock? My assumption is that it just spreads on to whatever it comes in contact with, yes? So, if I leave one or two rocks with the encrusting sponge and don't have them near other rocks will I be safe in preventing the spread? Thanks!

[bertoni]

It will spread on contact, certainly, but sponges also have a free-swimming reproductive phase, which might enable it to spread throughout the tank. I find that the coralline is able to outcompete it in areas with a lot of light, if your rock has the same animal that my rock does.

[weld1jac]

That's what I was concerned about. Since my preference is to encourage the coraline algae and other critters I think I'll be removing the present growth from the live rock. I'd just hate to put it in the tank, thinking that I could contain its growth, and then find it growing on everything. Thanks so much for the assistance. This discussion forum has been extremely informative.

[bertoni]

Sounds like a plan! Good luck!

[Avi]

Is this the same as what you have?

http://img.photobucket.com/albums/v58/Avrumeleh/UNKNOWN8505LR3778.jpg

[lovet]

I have this live rock with some green algae on it. I think some if it died and is a brownish or grey like color. Is this that hair algae or do I just let it grow?daywalkere@cableone.net

[weld1jac]

Thanks for the reply Avi, and the picture! The stuff on my rock unfortunately doesn't look anything like that. It's thick, velvety, and dark purple red. Very smooth. If you pull up a piece it's green underneath---it comes off in sheets. There aren't any "hairs" or such.

What is the stuff in your photo? It's interesting!

[Avi]

well, the stuff that's in the pic has been on a rock in my reef since I first set it up. It started off looking like what you describe...thick, velvety and dark purple red, but then changed to this. It gets greener at times but for the most part, it's a maroon/red.

I've been unable to identify it despite having posted here in RC in a number of forums, other to be told it's some kind of coral...the white "dots" being the "mouths" that indicate coral as opposed to any other kind of life form. But, I haven't even been able to get an idea of the family of coral that it might belong to.

[weld1jac]

Very interesting! I haven't been able to find any photo that resembles this stuff on my rock either. I've googled just about every combination of words to describe it but the images I find aren't comparable.

Just out of curiosity, how large is the stuff in your image? What I've got covers several larger rocks (about 10 pounds each) and appears to have begun growing on others.

By the way, I just took a look at your photo gallery. WOW!! Your pictures are stunning! Someday I hope to have a tank that looks like yours. As I mentioned in the beginning of this thread I am new to the hobby (had a FO tank about 15 years ago) and will be setting up a 55 gal tank I purchased from a friend. I'd like to evetually do a reef tank---the only thing stopping me right now is $$$. I'll upgrade as I can...for now I'll just get the tank set up with the live rock and sand, let it cycle, get my water to peak quality, and then add a few reef-safe fish. I want to get a pair of percula clowns and my daughter is planning to add a coral beauty.

Thanks again for your replies----you guys rock!

[Avi]

Thanks, weld...That coral in the photo is about three inches by three inches now...it's been spreading but fairly slowly...I'd say it is four times the size that it started at over a period of about three years.