My amazon swords have been growing really slow and developing brown edges. They are in a discus tank so the water is about 84 degrees. They are in clay pots so that the tank has a bare bottom to keep the water cleaner. I use Florapride fertilizer every time I do water changes and don't have carbon in the filter (I have been told it removes trace elements the plants use. Is it the heat or would some root tabs fix it? If so, are root tabs gonna change the chemistry enough to hurt the discus?