My newest tank (47g column) has been running for about 8 months now (livebearer) and again i've never had any problems. Yet, within the past few days i have been losing fish like crazy. I do water test every 2 weeks and i've never seen any nitrates, yet yesterday my nitrates were about 60ppm and the ammonia is sitting about 0.25. My gold nugget pleco has lost all his color and that is the last fish that i want to loose. Please help me!