Aquaclay

Can anybody tell me about aquaclay and how good is it to use

i think its a qood substrate if you planning to have a planted tank, coz its really good for plants.
it so much lighter than gravel, red in colour

I have been told it can be used in your filter as well but the person i was talking to just sounded like they didn't know much about it

filter ?????????? hmm never heard of that
isnt it sold like in 50L or 100L bag ??
this thing is quite light , so they sell using the volume not weight

was told it is a gravel as well as large balls for a filter

yeah u can get the larger ball ones to use as a filter element.. dunno how good it is though and they are double the price of the granulated ones...
but like DR.V said, it is a great subtrate for plants.