Hard White Spots On Bio Cube

[bothfly]

Have a 29 gallon Bio Cube setup for about a month or so now.
Noticed some hard white deposits on the back black plastic wall. One even looks like a tiny starfish.
Any thought?
Thanks

 

[zesty]

could be some coralline die-off. Mine will turn white when from time to time.

You could get in there with a scraper or something, it should come off relatively easy.

 

[moulton712]

Sounds right. I get them in my sump in the return chamber if my ato runs out of water

 

[Scubafrog]

I have the same white spots on the back wall of my Biocube. I always assumed that it was salt or calcium deposits. Seems normal as I have seen it on many Biocubes. I bought a plastic putty knife at the hardware store to scrape the back wall of the build up that is brown. I leave the purple coraline as it is harder to scrape off.

The tiny white starfish could be an Astrea (Asterina) starfish. I had a few Astrea stars that were in my live rocks. There seems to be mixed opinion on if they are good or bad. As long as you don't have an infestation or you don't see any damage to your zoas (if you have some) then I would leave it in the tank.

 

[bothfly]

Thanks guys....