Not to trying to high-jack your thread, but unfortunately, I'm in the same boat here and rather then start a new thread I'm interested in finding out where I went wrong. Hopefully others can learn from this.
I've a starfish in my 90gl, believe which is some variant of Astropecten articulatus (Royal starfish?), which was a hitchhiker through a livesand order from TBS.
Picture from 10 Nov when I added other critters
Star fish 10 nov by
E, on Flickr
Typically it's lived under the sand, only coming out during daylight on random occasions but quickly going back under. Monday, I noticed it was no longer going fully under the sand during daylight hours, only partially covering itself. I did see a red brittle reaching out to it at the same time.
Monday AM by
E, on Flickr
Tuesday I noticed the tips of 4 of its 5 arms looked like they were cut off, and one arm looked like 1/5 of it was missing. Wednesday night, I noticed one of the arm's looked like only 1/5 was left. Unfortunately my quarantine tank is still cycling and has high ammonia levels otherwise I'd have moved it out, and, I haven't been home these past 2 days due to the holiday so I currently do not know its fate. I'll be home later tonight.
Sitting out in the middle of the tank
Starfish by
E, on Flickr
Picture of its Arm, only 1/5 left
Starfish by
E, on Flickr
Tank is a 90gl, with a 20gl sump, 10gl refugium. Theres 120+ lbs of live rock, around 240lbs of sand between the refugium and main display. Skimmer is up and running well, and I started running carbon through two of the media reactors 4 days ago.
Tank was setup on October 15
First half of live rock added Oct 28 (when starfish was added)
Second half of live rock + more critters from TBS package added 10 November
Water quality constantly monitored and water changes done during cycling process, and ammonia never got very high (highest .8, but water change done immediately).
RODI water used since tank start up for both salt mixing and ATO. Mostly 0 TDS prior to mixing salt, as DI unit run's out I've been ok with it getting up to 2 TDS as I wait for a new order or resin.
A 10gl ATO reservoir is used for auto top of.
Water readings from 21 November all using Red Sea test kits:
Ammonia 0
Nitrate 32 (high... working on this)
nitrite .1 (high)
Alk 6.72 dKH (low),
calcium 420
iron 0 (low per test kit),
magnesium 1200,
potassium 425
ph 8.2
salinity 1.025
temp Avg 80.5F
I'm using Tropic Marin Sea salt, not dosing anything else but just ordered red sea supplements to start raising the Alk, and have a Calcium Reactor on order through LifeReef.
I haven't observed anything eating/picking at it the starfish, and it doesn't appear like theres any kind of fungus or anything else eating away. With that said, I suspect some of the other critters are picking at it while it sat out in the open, likely the crabs or hermits. Theres no fish in the tank, but there are a lot of crabs, and 3 other brittle starfish. Lots of hermits, snails, and 2 peppermint shrimp.
Its possible it ran out of food. I tried to feed it some pellet food the other day, but it didn't budge an inch for it while every other critter in the tank went crazy.
Any thoughts on where I went wrong? My best guess is because these things are sensitive to water quality, the fact that my Alk is low with present Nitrite and Nitrates that while it appeared healthy to me, that over the past month its taken on too much stress and just went downhill.
Appreciate any advice and how to prevent this in the future.
Thanks!
-Eric