This is information for man-made ponds.
There are four different types of water plants for a proper pond balance:
should be planted in a large pot in heavy soil & not commercial potting soil. Lilies should be set in pond to a depth of 3-4′ and they should be fertilized with a proper aquatic plant tab.
If you have older bulbs they can be divided every 2-3 years, depending in variety as they grow quite rapidly, and need to be fertilized every season. For winter cut back & set in bottom of pond or bring in house in a cool place for winter.
Some are planted in a boggy situation or up to 12 & 18″ of water. Most marginals are happy in 3-4’of water.
Such as Water Hyacinths & Water Lettuce. These plants are not hardy in Canada. They do best in full sun. As do all plants and the floaters are happy with a special fertilzer for floating plants, such as Flora Boost.
Hornwort which can be planted on the bottom or just thrown in loose but it is tidier planted. Elodia which must be planted in a container on the bottom. It grows high and is very ferny. It is real hardy as well.
All water plants are usually fertilized when you buy them but if they are to perform well for you, you should fertilize them once a month with proper Aquatic fertilizer. NEVER use ordinary plant fertilizer.