Thank you guys! That is a bummer that EC is pretty much useless to me as a plant root base to my substrate. Arggg...too bad I bought it already...so, I will try it out over the soil in one tank like suggested and then cap with sand in the other. I am curious though, when I sir the sand every now and then, will I make a mess of it getting soil mixed in? Or, will the soil be pretty firn so it won't get picked up by the swirling current from sand stirring?