If you are doing a small water change weekly, you shouldn't have to add anything to the tank, other than carbon periodically, and depending on your bioload IMO!
When you start talking reef tanks, then the possibility to add additional elements on a routine basis becomes more prevalent and with more importance, especially with a very diverse livestock population! _________ 125gal.w/Mag9.5 return(dual megaflow)>Mag7 pump Aqua Cev180skimmer.Wave2k Hamilton Reefstar(2)250watthqi(mh)pend.a Yellow, Naso Tang Red Lip Blenny Percula Clown Demoiselles Niger Trigger F. Wrasses Ceriantharia Orn.Shrimp and Stars Hermits Queen Conch asst. snails> Stars Zoos shrooms Montipora Brains Gorgonians Favia Turbinaria(large+small polyp) Acropora Xenia Tridacna (CroceaMaximaSquamosa) Leathers <35+75gal.reef tank as well>
"IF THE PHONE DOESN'T RING...IT'S ME"  jb |