i have a fairly new Echinodorus 'Rosé' and it is about 12 inches tall with alot of leaves, they were all green when i got it and now about 2 weeks later some of them are turning brown around the edges and some have completly turned brown. there is new growth and lots, since i got it 2 new leaves have grown completly and there is another shotting up 2 inches as we speak. should i remove the brown leaves or the ones turning brown? if so how should i go about it?