I could see two different colors of sand getting mixed together if you dig in it too much but isn't EC more like small gravel as far as size? If that's the case I don't see how it would mix?
Found this interesting, Taken from
HERE
Quote:
|
If you're planning a planted tank substrate should be layered, with a bottom layer of finer substrates first, like laterite, kitty litter, flourite mixed with a handful of peat moss works really well. Topped with a layer of gravel or larger sand will make a great planting substrate.
|