Wow this made me feel like a kid again, thanks for the direction Tom. I lined the bottom of my 120gal and I covered it with eco at the back of the tank where all the larger plants go, and fluorite black sand at the front half where my HC goes. But what a process, I had to do three batches before I had enough and it took me all night. I started elbow deep in mud mixing off the floaters. After I had several pots of boiling mud on the stove at once and got hit with many boiling popping mud bubbles, had to do a few rounds of this. The rinsing after you boil them was next to impossible for me. I let the mud pots cool and by that time most of the casing had dropped to the bottom, I would try to carefully poor off the watter on the top trying not to let the castings mix into the watter again. Once I had most the watter poured off I would fill with watter again and repeat. I did this over a dozen times on each pot but never did my watter run clear. I dried them under my tank lights over night and was able to mix them with sand the next day. In the end I ended up with about an inch of casting mix to line my substrate. It was a tone of work so I hope it work as good a people say.
About rinsing till the water goes clear, was I doing that wrong or does anyone get it clear?
After adding the rest of my substrate, filling the tank with watter and planting it I still had no water clouding.