Help IDing something in the tank

[OgreMkV]

These things are growing very well right now. I have no idea what they are. Someone suggested gongorian stalks?

Tank info
46g bowfront
96W 10k, 96W dual actinic PC lights (5 hour cycle)
30x flow from 3 powerheads and the skimmer (remora HOB)
Tank is cycling with 45 pounds live sand and about 45 pounds live rock.
Ammonia .25ppm
Nitrites = barely detectable
Nitrates = barely detectable
SG = 1.026
pH = 8.1
temp = 80F

So, any idea what these translucent white stalks are? They are growing rapidly. At least 1/4 inch to 1/2 inch per day.

They almost appear to have polyps on them, but they polpy looking things are spaced very far part on the stalk. These are the best pics so far, a macro lens for my camera costs mega bucks...sigh.

 

[sassafrass]

It looks like a type of sponge to me .Is it soft? If so it is a frequently encountered filter feeder , their population will diminish with lowered nutrients.
Lee