I have allways had problems with my pusling xenias. I thought the ones I had now were doing good but they are starting to nub up. I don't know what is doing it of how to prevent it. I add iodine, irion on occasions. And some other casuall supplements. I have halides and t5 lights. But the pulsing xenias just start to shrink up slowly until after a while there is nothing left. I want to stop and prevent it. What should I do