the leaves of my water lotus are discoloured - areas of an unhealthy brown color. this caused the leaves to crinkle a bit and the whole plant then looks so sorry. what i've been doing is to trim off all the leaves and let new ones come up. it helps but the solution seems like a temporary one because the discoloration appears again after a while. even new leaves come up with the discoloration and wrinkling. can anyone advise me? thanks ever so much.