It looks like mold on my sand? My zoas were all closed up today, and I discovered this patch at the back of the tank. I would just vaccuum, but I have a DSB and I'm concerned what I'd release into the water column would be worse than whatever this is.
Tank has been up since November, 2g water change weekly on a 13.5 Fluval EVO, stock is two clowns, two baby urchins, and lots of snails/hermits. Corals are zoas, cloves, candy cane, and a toadstool. I don't have all of my parameters handy, but they've been stable for months aside from an unusual .5 nitrite reading this past weekend (Salifert). Ammonia was negative, nitrates around 10, phos is high at about 1.8 - 2, but it's been stable there for months no matter what I try to do to get it down. Using stock lighting, ceramic biomedia, floss, carbon, and chemi blue for filtration.
Tank has been up since November, 2g water change weekly on a 13.5 Fluval EVO, stock is two clowns, two baby urchins, and lots of snails/hermits. Corals are zoas, cloves, candy cane, and a toadstool. I don't have all of my parameters handy, but they've been stable for months aside from an unusual .5 nitrite reading this past weekend (Salifert). Ammonia was negative, nitrates around 10, phos is high at about 1.8 - 2, but it's been stable there for months no matter what I try to do to get it down. Using stock lighting, ceramic biomedia, floss, carbon, and chemi blue for filtration.