So I have had my tank setup for 3 months and have had high nitrite levels for the past two months that wont seem to go away with treatment suggested by my LFS and water changes. All other levels are normal and no ammonia is present in the water tests. I have java moss, wisteria, amazon swords and java ferns. Fish are two panther catfish, white convict, firemouth chiclid, spotted puffer, two chinese algae eater and one mono. I have visited 3 LFS and each tests my water says no ammonia present but high nitrites and then they sell me a product they believe will remove the nitrites but none have worked so far please help I am going nuts over this.