What constitues 'overstocked' and what does it actually mean?

That about sums it all up.

 

Would a tree or ball sponge count as something you could have that might possibly make a noticeable difference? It is a filter-feeder. Just curious.

 

I had a conversation about this on another thread a little while ago. It's possible that a large enough sponge (don't quite know the necessary size, as I haven't heard of anyone trying this) would perform this kind of function, but not directly. They only absorb a select few nutrients directly from the water.

The reasoning is that skimmers are very good at removing planktonic diatoms (check the silica levels in your skimmate sometime; they're very high). Diatoms eat nitrates, and sponges eat diatoms. So, they'd be removing an algae that eats nitrates. If you removed a piece of the sponge, you'd have nutrient export, in a manner that's somewhat of a combination of running a skimmer and running a fuge with macro.

 

Wow, that's a good argument. I like it.

 

Clams like a little nitrates. I still shoot for 0 nitrates though.

 

So do I, and I'll probably try it some day.

I think it'll definitely help with keeping other filter feeders alive, since you're not skimming out that stuff. I don't know how well it'll work for a 0 nitrate system, though, since skimmers are very efficient.


EDIT: I just read a bit through the Book of coral Propagation, and it actually mentions using sponges in a refugium and gives it a couple paragraphs.