Alright, so I did a water change yesterday, and picked up a couple things for the mineralized topsoil. I couldn't find muriate of potash anywhere, but I discovered that all it is, is potassium chloride. Which is used in some types of ice melt, some types of water softeners, and is the main ingredient in NOSALT (a salt substitute) So I picked up some nosalt, as it was the only potassium chloride I could find. I also got some cork (more on that later) and some HC from my LFS.
I also had a hard time finding "pottery clay" I had some clay at my house, but it's grey, not red. And since you need the clay for iron, which I assume is the reason the clay is red in the first place, the clay I have probably won't work. So I did a little brainstorming, and vuala!! I have steel wool! So I grabbed some steel wool, put it in a tupperware container, filled it with tap water, and by the time the water evaporates, the wool should pretty much be in powder form. It's been two days, and there is alot of iron oxide in the bottom of the tupperware. Also, just to make sure that there will be iron in the tank for a long time, I wadded up little balls of steel wool, and encapsulated them in clay. The clay isn't waterproof, so the steel wool should oxidize inside the little balls, and slowly leach the iron into the dirt. I'm guessing they will last for years this way, as long as the clay doesn't break down too quickly.
With the cork, I made a small planter on the very top of my slate wall (pics to come) And I made a very tiny amount of mineralized topsoil. I found out from an old post by Tom Barr that you can mineralize topsoil by boiling it for about 10 minutes. Fortunately I have a loving wife who didn't mind me boiling dirt in her pots.
So I boiled my dirt, mixed in a little nosalt, and some of the steel wool water, and poured it into the planter on the wall. It was probably only about 4 or 5 tablespoons. Then I planted the HC in it. So the HC is sitting about 3 inches away from the 15 watt light, under 3/4 of an inch of water. I think this should be plenty of light for it.
The reason for the cork is because I've seen people grow HC emmersed in ripariums where cork was used as a planter. The HC will attach to the cork pretty firmly, so... hopefully the HC will grow out of the planter, and attach itself to the cork, covering the entire top of the wall with a nice, green, lush, carpet.
I'll post some pics of the planter, and steel wool clay balls later. Hopefully tonight, if I don't get too busy.