white things

Question
HI,
I have a 125 gallon tank with lots of live rock,coarls and 4 fish.
The tank has been set up for 3 months all is doing great including
water quality. My question is I have these white sponge like things
growing on the rock 5 that I can see, they are almost pineaapple
shape smaller than a half inch. They also only seem to grow on the
under side of the rock.Can you help me figure out what these are.
Thank You,
Butch


Answer
Hello Butch,

If they are sponges, then it is a good thing.  sponges are filter feeders, so they are filtering the water that they are breathing..  Sponges do tend to grow in the dark, or on the bottom of rocks...  They can not be exposed to air.  So, in other words if you were wanting to get rid of them, that is how you would do it...  

some folks dont like them as they tend to not look 'pretty'.  so it is up to you.  personally, i kept mine.

good luck, and keep me posted...

bill