Hi.......I have a yellow clivia that has been booming sizewise the past two years, kicking out some terrific offshoots. Has only bloomed once for me since I got it, but that's OK for now. However, over the winter a white fluffy substance began appearing on many of the leaves---top side and underside. Some of the newer leaves are now 'mottled' in appearance, rather than plain deep green. I've wiped the leaves clean as best I can with lightly soapy water, but the white stuff keeps coming back. The plant spends the winter on my enclosed, heated porch about 2' from a glass door where it gets a fair amount of indirect sun much of the day. In the summertime I move it outside into semi-shade (with two other clivias that are doing just fine.) Naturally, I'm concerned that the white substance is something "evil"---LOL---and would like to eradicate it before it does any permanent damage to the plant........For what it's worth, I did not water the plant from about November 1 until the middle of February. So it hasn't been sitting in a moist environment---in fact, probably a bit on the dry side overall.........Thoughts? Thank you!