I would use entirely Eco Complete or ADA Aquasoil. If cost is an issue, you can get 100lbs of Black Beauty Blasting Grit for around $12 or 50lbs of SoilMaster Select charcoal(color) for about $16.
Here is a good calculator to help you decide how much you need. If you choose to go with the blasting grit or the Soilmaster, you can pretty much figure it by Eco Complete. I really would not use the Estes stuff, its really not that nice, its to big and you'll be unhappy with it in the future.
Good luck and welcome to APC