Live rock looks like it's dying...

[jester]

My live rock is turning white. I use pure ro/di water and add calcium suplimented with trace iodine. Any ideas??

 

[thomas712]

Whats the alkalinity like, how old are the lights?
Thomas

 

[jester]

Good question. What should it be at?
Lights are about 6 months old. 3-175 MH and 80watt of antic.

 

[jester]

Full coraline encrustend. Tank only has a yellow tang, starfish with 2 legs the size of a quarter, a real small sallylight foot about the size of a dime, 1 scarlet crab and a cleaner shrimp. Same as before. Nothing has changed except the tank, lights and water.

 

[thomas712]

Recommended values for alkalinity vary depending on who's work you read. Natural surface seawater has an alkalinity of about 2.4 meq/l. Following are levels recommended by various authors.
From John Tullock (1991) "The Reef Tank Owner's Manual":
page 46 - Alkalinity range should be 3.5 to 5.0 meq/l.
page 94 - Alkalinity reading of 2.5-5.0 meq/l is proper.
page 188- Alkalinity should be about 3.5 meq/l. (In reference to maintaining Tridacna clams.)
Albert Thiel (1989), in "Small Reef Aquarium Basics" recommends 5.35-6.45 meq/l. This is an artificially high level which may initiate a "snowstorm" of CaCO3 precipitate. Most reef aquarists do not believe in such extreme and unnatural levels and recommend 3.0-3.5 meq/l as a good range instead.
A little Cut and paste
Thomas

 

[jester]

Any other ideas?

 

[mlm]

What is your calcium level at?