Hard COral Diseases?

[Nexus13]

ALl of my hard corals died suddenly.
I only had three but it still makes me really sad!

I had a tri color nano acropora
a neon green milipora
and a birdsnest frag

They went white from bottom up. All the color dissapeared and they kinda got flaky after that.

my softcorals all seem okay.

anyone have any idea what could do this?

[Nexus13]

i should add they all died over a period of two days. I fragged one piece of nano acropora and it seems okay right now.

[i have crabs]

any changes you did to the tank?
were there all new corals?

[lorenz0]

what are your parameters...

[JDigital]

.. how old is your tank?

[Nexus13]

tank is over a year and half old

the hard corals that died have been in there for over 5 months

all my parameters are good (or so i thought)
pH = 7.9
Ammonia = 0
nitrate = 0
nitrite = 0.1
phosphate = 0
calcium = 380mg/L

yah all my fish are good,
soft corals are fine
just the hard corals all died very quickly.

i looked it up on the net and it sounds like
Rapid Necrosis.

anyone else had or know of this?

in terms of changes:
i did add a neon dottyback
and some porcelain crabs that didn't make it.

[Nexus13]

tank is a 29 gallon with a 10 gallon sump underneath

[fencer]

Yes it is RTN. There is another thread about this happening in the spring. I recently lost two colonies for no reason. Others have had similiar happenings and those people know how to keep SPS's

[findingnemo1]

What is your DKH at?

What do you dose to keep the DKH,Calcium up?

[banditpowdercoat]

You don't have an anemone by chance, do you? My Anemone just made half my Hydno dissapear. Apparently they dont get along LOL