What's going on?

[junxu95]

Folks,

My tank were in good condition for more than 2 months. However, my sand bed suddenly covered brown dirty stuff with lots of air bubbles a few days ago. Also all my live rocks became yellow and today turns to black color with lots of hairy things. I tested nitrate, nitrite and PH, and they are all good. I am just wondering what's going on with my tank? Seems I got serious problem here.

I changed the slat from "Instant Ocean" to "Premium Marine Salt Mix" tow weeks ago. ALso I recently start dosing calcium and iodine.

What should I do right now to clean off this mess? I would really appreciate you folk's help.

[sir_dudeguy]

it could be because of the change in salt. When you change salts, there are different levels of this-and-that, so something is bound to start growing (or stop for that matter) when you change salts. I'm not positive what the black stuff would be w/out a picture, but the brown in the sand could be just diatoms (which are common when switching salts)

[Sk8r]

Or cyanobacteria. Stop all additives except calcium. And test for calcium: you should not go over 450. Are you using kalk or dkh buffer? Your alk should be 8.3 or thereabouts. Sir Dudeguy has it right: salt changes are a problem. Go back to Instant Ocean, imho. That was your setup.

Get tests for : salinity; temperature; alkalinity [Salifert]; calcium [Salifert]; ammonia, nitrate, nitrite [strips will do], and report back. Turn out your lights for 3 days and see if that helps. Do a 20% water change and slow way down on feeding. Do NOT use Chemiclean: your tank is too young. Give us relevant parameters and let's see what we can do to straighten this out. Report all tests, report all measures taken. Where are you getting your water? Ro/di? What is in your tank? How much rock? What kind and how much sand? Fishes? Corals? Inverts?
No fish will starve in 3 days.
Do you have any filters or sponges in the water flow? These can be a problem?
Give us a good description of this tank.

[junxu95]

Sk8r/dudeguy

Thanks for the reply. I make more tests tomorrow in the day. I have 5 chromia, 2 clownfish and foxface Lo. in the tank. I don't have many cleaning clew. Only 3 hermiit crab, 1 turb snail, 1 nass. snail, 5 cerith snails, and 1 sillylight foot crab. 2 cleaner shrimp and 1 pepermint shrimp. 1 bubble Anemone. I use RO/DI water since the tank setup. There are 100lb LR in my 70G tank. About 4'' sand bed.

I have a 20G sump with 1 small refuge chamber. I got a sponge filter bag in the drain chamber, but it has been there since the tank is setup.

I think I will try turn out the light for sometime, but not sure if my anemone will be ok.

[drummereef]

Brown algae with air bubbles sounds like dinoflagellates to me. They can be a pain to deal with. Can you get a pic? Read this for more info.

http://www.reefkeeping.com/issues/2006-11/rhf/index.php