Problem with Kelp??

[Mcasteel]

I feel like I'm the only one with this problem because all the pictures of reef tanks I've seen don't have any plants growing in the main tank. When I first added the rock to my tank, there were no signs of plant growth except for some green macroalgae in a few spots. Over the last couple months, several rocks have been overgrown with a yellow kelp. At first it looked okay because there were only a few strands. I took two rocks out of the tank last night and used pliers to pick it all off. I realize it is growing because there is a food source, but I'm not overfeeding. Could it just be lighting that is causing the kelp growth? My water parameters are stable and ammonia, nitrates and nitrites don't register.

[landlord]

There is undoubtedly a food source in the tank. It might be registering at 0 because the algae is using it all up. Lighting alone won't cause growth.

FWIW --landlord

[fishysteve]

Do you have any pictures of the kelp? I've never seen kelp in an aquarium before.

[Mcasteel]

You can see it in the early stages around the edges of this rock. It starts out with pointed leaves growing from a central stem. Then the stem proceeds to grow upward with small branches coming off of it. It has small balls attached where the leaf branches from the stem. I did some research and apparently the balls are for buoyancy. I would have attached a picture with the kelp growing in a long strand, but I've pruned them all off the rocks. I'm sure they'll grow back and I'll be doing it again soon.

http://i157.photobucket.com/albums/t59/grunge5172/q-DSC02910.jpg

[reef1973]

Neat!!! I thought kelp only grows in cooler water.

[Mcasteel]

After more research and scouring the internet, it turns out that my first identification was incorrect. It is Sargassum hystrix, a type of brown algae that sometimes grows on rock from Fiji. Since it does form bladders to sustain buoyancy, I assumed it was a type of kelp. If I was going in a different direction with my tank, I'd consider letting it continue to grow.

[LorenzoDM]

Enjoy it while it lasts. I had the same stuff when I started my reef tank with new Fiji live rock. It grew like mad for the first few months and then it all just died off and never came back. Maybe the warmer water caused it to die off. Now I miss it because it's something different you don't see every day :sad2: