Sand Sifting Star lost all but one arm

[moonracer0]

I've had this tank for about a year now. I had two fish that died a long time ago and just started getting cleaners to keep the algae off of the glass and live rock. I started with 3 hermit crabs, 3 cleaner shrimp, and 4 turbo snails. Well, the shrimp died off first, then one-by-one my hernit crabs died. They didn't even get a chance to molt. So I went and got two sand sifting stars. Then over a weeks time my snails died. Now I have one sand sifting star this is fat and happy and the other one is really sick looking. He has lost all but one arm. I know they will grow back but it's been about 2 weeks now and he still doesn't look good. I have them in a 55 gallon with medium water flow. An AC110 and protein skimmer that can be used up to 150 gallon tank. Here are my parameters:
Nitrites 0
Nitrates 0
Ammonia 0
pH 7.8-7.9
Salinity 1.020
Like I said I had this tank for about a year now. I have 3-4 inches of live sand and 40lbs of live rock. I have been afraid of getting any more fish after my yellow tang died about 6 months ago.

Please any advice would be appreciated.
Thanks

 

[1journeyman]

Welcome to the boards.
First off, get your salinity up. How are you checking it? Salinity for inverts needs to be 1.024-1.026. Low salinity/fluctuating salinity can be deadly to inverts.
Have you ever medicated the tank? If not, good; Don't. Some copper based medications can be toxic to inverts for a long, long time.
Sounds like we need to start at the beginning. What fish do you currently have? Be sure to research your fish/invert purchases. Tangs in a 55 are a bad idea, and Sand Sifting Stars will starve unless they have huge sand beds (hundreds of gallons). Stars are also very sensitive to fluctuating water parameters and low salinity.

 

[moonracer0]

First of all, my salinity was fluctuating, badly. I have one of those plastic hydrometers, which I know isn't the best way to check your levels. I plan on getting a glass one soon. Anyway, my salinity was up to 1.028 a short while ago. I did a 25% water change and since then it's been around 1.021 - 1.022. I haven't put any medication in the water for fear of hurting the healthy star. I don't have any fish in the tank, but plan on getting a couple of damsels. Not too sure about the damsels because of their territorial nature. That's one reason why my Tang died. I had one Tang and one damsel that had survived the cycling period (the damsel only). The damsel would not leave the Tang alone and it died from the stress of the damsel attacking it. Anyway that was about 6 months ago. I talked to the lfs here and they said that I had enough sand for two Sand Sifting Stars. I was trying to get a cleaner to keep my sand clean and they do an outstanding job. So do I need to add some fish? Is the one star not getting enough to eat? It just looks so sickly. Here a pics of the two different stars. They're not the best pics.

 

[sepulatian]

The SG fluctuations are damaging your star badly. Stars need a constant SG of 1.026. They cannot take fluctuations at all. They can be at 1.025 if the SG stays there. stability is the important factor.
I talked to the lfs here and they said that I had enough sand for two Sand Sifting Stars.
I am afraid that your lfs is just trying to sell you another animal. You have a 55 with a 3" sand bed. You don't have enough to sustain this star for long. Sand sifters live off of microbes in the sand, they do not eat detris. You need nassauris snails, hermits, bristleworms, ect.

 

[1journeyman]

Originally Posted by sepulatian
...with a 3" sand bed. You don't have enough to sustain this star for long. Sand sifters live off of microbes in the sand, they do not eat detris. You need nassauris snails, hermits, bristleworms, ect.
Much less the 2 they sold him.
You must get a glass hydrometer or Refractometer and stabilize salinity immediately if stars are to have any short term hope.
I'm going to get Ophiura (our resident expert on Stars) to look in here. Having said that, I think most Sand Sidting Stars eat critters and micro organisms out of the sand, not detritus.

 

[sepulatian]

Having said that, I think most Sand Sifting Stars eat critters and micro organisms out of the sand, not detritus.
I completely agree. I am interested in Ophiura's take on this as well.

 

[ophiura]

The specific gravity is fatally low.
As mentioned, the fluctuation was worse...but it would have been better to be honest if it was left at 1.028, then to come back down. I'll take too high over too low.
I don't see info on how you acclimated it?
Without a doubt, it is acclimation shock.
IMO, it is not likely to recover, but anything is possible. It is possible the other star, too, will start having trouble (the signs usually pop up within a month of introduction).
There is also no real doubt in my mind that a single star - let alone two - will starve to death in this tank in 12 to 18 months. Typically they can not be spot fed, and they are EATING the creatures that keep a sand bed healthy and clean. Some will survive, now and then, but I wouldn't count on it.
I would raise your specific gravity SLOWLY over many days by adding saltwater for top off. Aim for 1.025-1.026

 

[moonracer0]

I want to thank all of you for your help. I will do as Ophiura suggested and raise my salinity slowly by adding saltwater for top off and get a a glass hydrometer. Just to let you all know I've had these stars for about 5 months. Will also closely monitor my salinity levels and make sure it doesn't flucuate any more.
Thanks again

 

[1journeyman]

Glad we could help.
Do some reading when you get a chance on sand beds. One of the often overlooked aspects of aquariums is keeping a healthy sand bed. The problem with sand sifting creatures of any sort is that they eat all of the beneficial micro fauna in an aquarium's sand bed. This leads to a less healthy tank (in addition to creatures starving).