Troi said:Hydroleca? Are you sure they aren't fossilised rabbit tuds, repackaged and remarketed for the likes of us rampant consumers? Either way good surface area, I can see why they might work well.
Honestly it is absolutely fine, in fact better than that. They used it a lot on the continent in all sorts of filters. <http://www.koi-dam-kalles.dk/4842456>This is the stuff I have in the shed, seems to have a pretty good surface area:
Alastair said:I've actually got those for my riparium planters, I'd say that unless you were to break each one up to expose the little holes inside, then not sure if they'd be very efficient. They are quite smooth on the outside.
Would be far better off getting Alfa grog instead.