Yes, I did have a Nitrate issue. I didnt realize in my sump I have a chamber in which I had BIO-Balls in it. Ive takin them out now...Do you think that Nitrates at 10--20 ppm for short time could kill them? And what is a reasonable Calcium level. I have 1 Monti, 1 Frogspawn, 1 Candycane, 1 flowerpot, Tree Leather, leather I think thats it...and what else should I be keeping track of with a new CR running...