[mudboots]

Tazcat - I bought .5 cubic feet of each and mixed them evenly. I would not recommend using this much sand in a large tank. The 20 should be fine because in the worst case scenario I can overhaul it, though it looks pretty stable at the moment. When I get back in town I'll take some pics to show how it looks after a few days of settling. For the 125 I'm going to wash out some of the sand and use more gravel, though all guess work so no ratios to post. I will mention that the sand mixed in made it extremely easy to set my plants in firmly so there was no shift when I added the water.

Alex123 - I used almost exactly 1 inch of the organic choice and an inch of the mix, and will do the same on the 125 (using less sand). This of course is pending how the 20 looks when I get back.

Anyone else learning from mistakes - Wait until you get good expert advice (thank you Diana Walstad) before you start experimenting. I learned the hard way at the expense of my son's pet AFC that too thick of a soil layer and too thick of sustrate on top really will cause some horrible problems. I could smell the swamp down the hallway. I'm just glad it was in a small tank and not the big one. However, I've learned that those little "guppies" we call mosquito fish down here can handle just about any extreme you throw at them, so if you absolutely HAVE to play around with ideas, try it on them first and you won't be out anything, especially since you can get them free from any bar-ditch or hole in the ground you step into.