After years of having plastic plants in my FWT, 2 weeks ago plastic was replaced with the real thing. I purchased about 5 plants -- don't know the names, but was assured by my LFS that they were no fuss (yeah, sure). Shortly thereafter, my water turned an amber color. I performed a water change and less than a week later, amber colored water again. I changed the water last night. Before adding, I tested the water, all was good. Purchased a new CF tube to ensure that the plants had the proper lighting - and it's on about 12 hours a day. I have a 16-gallon bow front with a bio filter, 6" inch bubble stone and sand. What LS is left is one loach and a shark. Lost the two angels. Can anybody tell me why this is happening?