Aquatic Crinum

Alani Davis
Wed, 09 Mar 2011 11:14:06 PST
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

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