On 16/08/2014 13:43, Chris Hogg wrote:
On Sat, 16 Aug 2014 12:18:02 +0100, 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.

Never used it, so can't answer your question, but Hydroleca is just a
trade name for Lightweight Expanded Clay Aggregate (the Leca bit),
widely available and probably a lot cheaper than Hydroleca. See
http://tinyurl.com/owjjpe5 for general info. At one time in Cornwall
large quantities (many lorry-loads) were used as fill in 'escape
lanes' at the bottom of long steep hills where lorries whose brakes
had failed could be brought to a reasonably safe halt. And no, I never
did avail myself of the resource (but I bet some did!)

If it does turn out to be a bit light (it may even float; it has a
malteser-like structure), you could always mix it with gravel to
weight it.


Allegedly it holds 40% of its own weight in water, which isn't a lot
comapared to vermiculite, but enough to stop it floating.