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.




Thanks, Chris. I had a look at that link and one or two images seemed
to suggest it might float. If it's really light enough to float, I'm
not sure gravel would help much, unless it was quite chunky.

Perhaps I'll just have to buy some and see if it sinks or floats. I'm
sure I could use the rest for top-dressing pots if I can't use it in the
pond.

--
Spider.
On high ground in SE London
gardening on heavy clay