40 Gallon s/w tank update

[Deniz]

Gday

Well, some might remember I ventured into the unknown that is s/w tanks. I've had it up and running for about 35 days now.

I now have 6 kilos of live rock and for the last few days an influx in organics in the tank. Here are some of the more interesting ones:

I have brownish algae-like matter growing on the glass which look like little trees up close.

I have a wierd brownish looking circle with fleuro-green spots around the sides on one of the live rock.

I have stuff that looks like macro-algae which has flourished since I installed the blue light as well as the white last weekend.

I have numerous crab-like creatures living in holes and one big crab with hairy legs which isn't so shy. He is about an inch in diameter if you include the legs.

I have a wierd looking white pod with a creature in it that comes out and hides if you make any sudden movements and shuts its own lid. It looks like a few hundred black worms. I think it is just one animal however no idea what it is.

Very interesting to look at.

I'm thinking of adding a few more kilos of live rock and if all parameters are still fine, an anemone and a week later some fish in a few weeks.

Should I be concerned about the crab? Does it need to be fed? Will it eat my fish? Any notes or guesses about the above would really satisfy my curiosity. Thanks :)

[benjen]

Check here and see if you can identify any of the things in your tank:
http://reefs.org/hhfaq/

The crab is more likely to be problematic than most of the critters you describe, but it's hard to say at this point. If you can give colors, where the rock came from, etc. people here might have an easier time guessing. Most crabs are omnivores, so if you make sure it stays fed, it may not be a problem, but definately watch it with other animals, as an unknown crab might have a preference for algae, other crustaceans, corals, or fish in it's diet.

Look up pictures of spaghetti worms and see if your 'pod' is that. If not, it is probably some form of coral, anemone, or hydroid. My button polyps turn into 'pods' when they feel threatened.

Generally, you want very stable systems to intentionally add an anemone. They are not tolerant of variable water quality or other features of new tanks and new saltwater keepers.

[Deniz]

Further description on the crab mentioned above: It is dark brown, has hairy legs with white stripes on the legs and black claws.

I saw it trying to pinch bits off a white part of the live rock.