Ok, thank you!I've had mine for about 2 years, but is beginning to look a bit off - nothing specific, just duller colours and not so active. Wasn't sure if it was a symptom of something or just age. He's in a 260 litre tank with 16 cardinals and 3 cory. Water stats 0 ammonia, 0 nitrite, 5 nitrate, pH 6.5, soft water. Am going to be adding more fish to the tank later, but obviously didn't want to until he was looking healthier.