"Spider" wrote...

I have been wondering about using Hydroleca as a substitute for aquatic
compost when potting up pond plants. There's probably a very good reason
why I've never heard of it being done, despite its being used for
hydroponics. Perhaps it's too light? I'd be interested in other urglers'
opinions/experience.


That is very light especially in water so any movement by fish and you will
have empty pots. The main problem is that it is nutrient sterile so you
plants will not grow well especially gross feeders like lilies not matter
how rich your pond water.
For lilies use good garden soil as long as it hasn't been manured/fertilized
recently, not even that "Aquatic compost" is good enough for them without
also buying their own fertilizer. (waste of money IMO). The soil should be
covered with pebbles but they must be big enough and heavy enough that the
fish can't move them and get in and suck up the mud to feed. For Goldfish a
goldfish sized pebble is about right, for Koi no pebble is big enough, cover
the pots with a wire mesh wired down well but ensure the fish cannot get
caught in the mesh but the lily can send up shoots through it.
--
Regards. Bob Hobden.
Posted to this Newsgroup from the W of London, UK