I set up my 75 gal
tank recently and decided to do the cycling the tank with out the use of fish method as described in the article on this site. I used two jumbo sized shrimp which have been in the tank for about a week. I have 120lbs of aragonite sand bed and about 40 lbs base/live rock and will be putting more in soon. My question regards the brown deposits that are forming on the sand bed, glass, and rock. Ammonia is still only at about 1 ppm
. Whats the deal with this brown stuff? It wipes right off the glass pretty eaisly and dissipates into the water.