Eco-Complete (black) will intially raise the PH as it has high calcium content to it (look on the label for the caicum content).
The only substrate that will look good mixed into EC is Flourite Black (not the sand type).
Using pressurized CO2, will also help to keep your PH from spiking as high initially.
I am no expert, but I do know this system works well. I have a 29 gallon planted tank with 1 bag each of EC and FB, that uses pressurized CO2. I also run my canister with a small amount of crushed coral to stabilize my PH.
Last edited by CRS Fan; 05-07-2010 at 11:31 PM.