Jerry - I am growing four forms of aquatic Crinum in an aquarium. I had some shakey starts but the plants are 10-20 years old now. I have not problem growing them in a fine gravel medium with an assortment of other aquarium plants like Cryptocorne, Anubias, Echinodorus, and Sagittaria, The gravel bed it is about 3" thick. I have tried to supplement them using slow release fertilizer pellets inserted into the gravel bed design for aquatic plants and water gardening though not very often. I was trying a number of the aquarium plant fertilizers and minor element supplements on the market in the aquarium industry and was greatly frustrated by the lack of or poor results I got. It seems that since I have stopped tinkering with the nutrients and other than changing the water and occasionally cleaning the filter, do little to the aquarium, I have been getting far better performance from the Crinums and other plants. The water temperature is about 76-82 without much variation. They do like intense lighting and I first had luck with metal halide fixture (250 watt) but great tired of the down sides of having a small street light in my living room. I now use a high output fluorescent fixture with four bulbs which is about 6 inches from the water surface. A previous experiment with a light box containing 6 typical 48" flourescent bulbs was not really bright enough to keep the plants happy. These were all either daylight bulbs or special wave length bulbs designed for planted aquaria or a mixture of both. I mention this because I am not sure what you mean by plenty of light and I have had plenty of bright light situations with aquatic plants that turned out to be not nearly bright enough. The aqarium is all in a "typical" 75 gallon aquarium 48"X18"X18" with variable platies the only fish in the tank at this time. The aquarium was fish free for about 7 years. Pictures of one the Crinums blooming are one the PBS WIKI. Oh, also despite what had been able to find out about their wild habits, I experimented with trying to get them to produce emergent foliage but cultivating them in a pond in the summer and slowly boosting the pot to create shallower and shallower water above crown of the plant. They won't produce emergent foliage and struggle without at least a couples inches of water depth. I used offsets from the aquarium individuals in the pond, and the Crinum calmistratum did much better in the pond than did the Crinum thaianum. None of them have survived a zone 8 winter so far. Alani Davis