Hello all

I'm thinking of setting up a tank with a Seachem Onyx Sand substrate and a
heater cable. Reading about heater cables, I've seen it suggested that it is
best to cover the cable with a fine sand which distributes the heat evenly,
then cover this with the rooting substrate. Is this the way to do it, or
would the cable work just as well in the Onyx Sand, which I'm guessing is
quite a coarse grade of sand (I can only find it online).

I'd be interested to hear comments about Onyx Sand too if anyone has any.
Messing about with substrates is such a pain when the tank is set up I would
like to get this one right first time, if possible

Thanks - Jon