Anyone Know a Thing or Two About Sponges?

I'm interested in adding a sponge to my tank to facilitate mechanical filtration and polish my water. I've heard they are relatively difficult to keep. I know they need high water flow, a somewhat shady spot to reside and supplemental feeding. I also know that they can't be exposed to air otherwise they're as good as dead. But other than that I don't know too much.


I had a hard time finding additional information about the specifics of sponge care. Do they need daily feeding? Growth rate? How much light is too much? What's the minimum water flow they need? I read a quick thing saying something about rapid algae growth being a problem, possibly growing in the sponge itself smothering it in the process. I'm struggling with brown diatomaceous algae right now, should I hold off until I get it under control? Some relevant tank info - 55gal with two K4s and 4 bulb T5 retro being overdriven by an IC660.

 

Thanks for the offer Adam. I live in Altoona, right next to Des Moines. It'd be a bit of a treck to Cedar Falls. I have a sumpless system at the moment and would add some to the display. Are they effective at polishing the water or simply filtering out the excess biological stuff that the corals don't consume. The main thing I'm trying to accomplish is polishing my water without the use of filter floss or other mechanical media that can get clogged up and turn into a nitrate factory relatively quickly. Are sponges an answer to this problem?