I have to repot some arum lilies which have not been in water and then
put them in our pond which has barcoo and bass in it. What sort of
potting media should I use so I don't harm the fish?


If the effect on fish is the factor you are being judged on, take care
not to use any conventional 'potting mix'. These usually have slow
release granules, fertiliser in them which in water would dissolve too
fast, possibly burn the new roots of the arum, and boost algae in the
pond making fish visibility difficult.

Arum lilies are heavy feeding plants and like a rich fertile soil, an
ordinary heavy dark loam taken from a fertile spot about a foot down,
mixed with some clay content for trace minerals should be adequate to
feed the plant without polluting the pond.

About a one cubic foot pot should be adequate for arum lily for a
couple of years, not so heavy you can't move it around, heavy enough
to cope with strong wind when there's some top foliage to blow about
and reduce any risk of soil spilling in the pond

A topping of large stones about 2" in size should keep fish from
interfering with the soil, lowering the pot in a couple of steps over
a couple of weeks should adjust the arum lily to a saturated soil
position

regards, andy
http://www.members.aol.com/abdavisnc/swglist.html
(andys aquatic plant list for interesting swaps)
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