I am trying to figure out what is causing this, levels are good. Some of the leaves on my Amazon swords are a nice green, others brown, holes, stringy and ghostly. They have been thriving since March of this year, been going backwards the last month. Weekly water changes. Only change was added a piece of driftwood 3-5" for my clown plecos a few months ago and cholla wood thin long piece for my shrimp. Any suggestions would be appreciated.