Lotus needs repotting every one or two years.  They may be uplifted from their pots in early spring while they are still dormant. Find a healthy tuber with at least two internodes and a growth tip.  Pack clay soil tightly in the same or larger pot as described above, burying the tuber so the growth tips are barely buried.  The other tubers can be repotted or given away.  Feed waterlilies and lotus once a month with an aquatic plant fertilizer tablet, and twice a month may be necessary when the water temperature is over 75 degrees Fahrenheit.  When winter comes, remove the foliage of lotus and hardy waterlilies and just make sure they are at a level where water won’t freeze down to their crown.  Tropical waterlilies should be taken from their pots for the winter and have all their dangling roots and leaves removed.  The rhizome should then be washed off then wrapped in slightly moist peat moss or damp newspaper and be placed in a plastic bag.  The bag should then be placed in a dark area of about 35-55 degrees.   Marestail simply requires to be thrown into the pool.  Attaching a rock tucked in a rubber band will keep them submerged if desired. Several may also be potted together in a shallow pan with gravel or sand in the pan.  When late fall comes, it is best to cut off the top several inches of the stems and bunch them together, weighing them to over winter on the bottom to avoid getting frozen.