Over the past few years I have grown several Nymphaea species including N. zenkeri, N. stellata and N. micrantha. All three have grown well - mostly I have removed emergent leaves to keep them in the submerged form but I have occasionally let them produce aerial leaves and the odd flower. The flower on N. stellata is stunning - a perfect bluey-white water lily but held much higher above the water than our native white water lily. My question is really around seasonal growth. I have found that all three grow well for about 3-6 months but then die back completely, rest for a few months and then resprout and grow again. I'm guessing that this corresponds with the wet season in the wild, but can anyone confirm that this is what they find as well? I tend not to remove them from the tank as I have done in the past with Aponogeton species so they don't seem to need drying out.