Re: Aquatic Plants Digest V6 #81

[Greg Morin <greg at seachem_com>]

>I am not sure about the composition of Onyx sand, but I do believe it is
>not so much a 'fertile substrate' but a special, awesome looking,
>substrate which you will possibly have to add slow-release tablets to
>(many apologies if my assumptions are wrong however seachem ;)).

Onyx does not contain any nitrates or phosphates if that is why you 
mean by "fertile". Howver it does contain all of the important macro 
and trace elements (calcium, magnesium, iron, manganese, etc).

-Greg Morin