Q-tip Sponges - What do they mean?

[gmann1139]

I just noticed that in the back of my tank, near the Protein Skimmer, I have an explosion of Q-tip sponges. I've had a couple growing in this tank for months, but there are literally a hundred or so growing on the back wall of the tank. They seem to be concentrated in one area, which is near the PS and filter intake, and probably the lowest flow area of the tank as well.
Now this tank just had an issue with phosphates that was solved by the installation of a DIY in-tank refugium. Nitrates were never higher than 10 - 20, but they're going down as well.
What is feeding these q-tips, and is it a good thing or a bad thing?

Thanks in advance.

 

[onyx]

Q-tip sponges, like several other species of inverts usually cycle out over time as long as the water isn't too nutrient rich. Their presence is a good sign and means that your aquarium is healthy.

 

[gmann1139]

So the fact that they've peaked just after I had a burst of cyano is probably not a coincidence?
And now that I have a fuge on that tank, they'll probably go away?

 

[reefkprz]

there is a chance of it.
they have just found ideal conditions the right amount of flow and the current brings them the food, it could be due to an increase in the right size of particulate foods they need. usually they go through spurts of population explosion then receed to very few or none. I have noticed I always have some in my protien skimmer chamber and over flow box, but no where else in the tank.