Sponges

I have noticed a few sponges come up in my system. I first noticed one on the shell of a snail I bought months ago. And even though three snail died, I did not remove the shell. I thought the sponge looked cool. There was also a couple of spaghetti worms on the shell. Anyways I was wondering what good, if any, do these things do in my tank? Should I remove them? How big will they get?

 

I am pretty sure there are thousands of different types of sponges. There is tons of debate regarding uptake of DOC and silicates, some use both for nutrition. Very few are photosynthetic. Sponges are benign for the most part, some preferring to grow in shaded areas or sump areas with good flow.

The only invasive sponge I have had was the Liver Sponge, and it was not really that invasive.

 

+1, most eventually starve/ die off on their own. from what iv read they brutal filter feeders (meaning they need a lot of food to sustain themselves and grow.) if you do some search in this site you should come across a few post and threads regarding sponges. i have one that is slowly dyeing due to the burying and re-aquascaping of my sand bed my diamond goby is doing.

the most common and persistent ones are the so called "pineapple sponges" called such due to their shape. should you wish to kill them exposure to air for a prolonged time usually does the trick.

from what i know, and as mentioned. there aren't many hazardous sponges that promptly appears on their own in our home aquarium.