I need more info.1.How long has the tank been up and running, 2.what are your ammonia, nitrite, nitrate, ph, spacific gravity readings readings. 3. Whats your temp? a heater is not used on most species unless there from a tropical zone. 4. Whats in the tank? ie. live rock? sand bed? 5. where did your water come from? Tap, ro/di, ro? 6. Did your test your tank for copper before octo was added? Copper kills cephs. 7 was the tank cycled?