four starfish

[cicadae]

The guy at the pet store who appears to be quite good at saltwater fish etc. recommended that I add four starfish into my 55 gallon tank. One was a blue linkia which died within a week. One is a dalmation linkia. It does not look happy. It hangs under the rocks and its ends hang down into the sand. The other two are sand sifters.
I think that this may have been a mistake. My water parameters are all fine. I have no fish, only crabs and shrimp at this time. The tank is not very old (maybe three months max). I have a lot of live rock and some really happy corals but not a lot of algae yet. I read that the sand sifters will eat until there is no more food and then die and decay under the sand. Already the remaining linkia is looking bad.
1. When linkia dies, is there an easy way of getting him out?
2. What do I feed the sand sifters to keep them alive or should I grab them while they are alive (they climb the sides of the tank at night) and give them a better home?
Thanks in advance !

 

[bang guy]

Linckia are very difficult and really should only be added to mature reef tanks. I see that you know that now.
The Sand Sifters can be fed by hand. A small piece of Scallop or Clam directly in their path can keep them going. They will destroy a live sand bed though.

 

[cicadae]

What happens to a tank when the live sand bed is destroyed?

 

[bang guy]

The filtration provided by the sand is reduced especially the nitrate reduction provided by anaerobic bacteria. Then without organisms slowly moving water through the sand and the infauna all eaten by the Starfish there is nothing in the sandbed to consume the detritus and it accumulates over years and rots. This phase is where PH fluctuates due to the released organic acids and Alkalinity becomes difficult to maintain. At this point is where corals will begin to look less than peak. It won't kill the corals but they won't thrive like they did previously.

 

[cicadae]

Thank you so much for your advice! We took apart the tank today and removed the dying starfish and the two sand sifters.
We now have a tank with lots of hermit crabs, a few emerald crabs, two skunk shrimp, one coral banded shrimp, a couple of snails, and several pieces of coral. We invested in a set of LED reef lights and the corals look great. I have fallen in love with zooanthids so probably need to get into the corals forum to ask what is compatible with what. My water parameters are good and have been for almost a month. In about a week or two we are considering getting a pair of percula clowns. in a few more weeks we may consider some wrasses. In total we now know that we should not have more than five smallish fish.
We did love our lawnmower blennie. I am guessing that we should wait for another 6 months to get another one.
Thanks again
We have learned more here than anywhere else.