yep. Free fertalizer. You will not believe how filthy that water is from that static filter. It makes me feel good everytime I clean it out because I know that is stuff that I have trapped and removed from my koi's environment. You could really just get a danner mag-drive pump....or really any submersible pump and put it in the bottom of that sump barrel. You could also just use a real sump pump too, since they are made for that purpose.