I repeated the "sugar test" with better results this time. It appears that the temperature gradient from front to back is pretty small, although it appears to be real. This time I took the same pan I had before (1/2 sheet insulated jelly roll pan), lined it with foil, and sprinkled granulated sugar over the pan as evenly as I could. I preheated the oven to 350F. It cycled at least two times, but I wasn't paying super close attention. I centered the pan on the middle rack and left it in for 15 mins. Results below: None of the sugar melted (the melting point for table sugar is 367F). This tells me that when set to 350F no part of the pan made it to 367F for any appreciable amount of time. The sugar did get a little tosted (to be expected). I then removed the pan and adjusted the oven to 375F. Again, it cycled at least two times when getting to to the 375F setting. The pan went in again in the same position for 15 minutes. The result is below. All the sugar melted in the pan, with the sugar that was towards the back of the oven browning more than the sugar towards the front of the oven (the top of the pan in the photo), indicating warmer temps in the back as observed before. What I have learned: 1) my ability to turn a knob to a set temperature in a reproducible fashion is questionable. 2) there is a temperature gradient in the oven cavity, albeit a small one (probably on the order of 8F or less when the oven is set to 375F in this case). The difference, although small, can be significant in certain cooking situations if other basic precautions aren't taken. 3) I am way too caught up in this and need to get on with my life! ;) BTW the oven door lock issue has not repeated itself. Perhaps the mechanism was just a little sticky when the range was brand spankin' new.

Bama - forgot to answer your question about cutting the gg's....just took my tile nippers, lined 'em up and (amid lots of moaning and grunting!) kept squeezing till they snapped! SOme were too thick for my strength, but a little picking and choosing to find the right ones made it work out OK. Pat

There shouldn't be any reason it wouldn't work as a significant fraction of a soil. I couldn't find any information about the size gradient, so it's difficult to get a feeling about what ratio of ingredients would work best. I'm thinking it's considerably larger than screened Turface and most bark you would use. Because it's going to hoild a significant volume of water (probably more than the bark but less than the Turface). I'm thinking that 3 parts screened bark, 4 parts of the grow stones, and 2 parts of screened Turface would be a good starting part. Some pictures of the product next to some screened Turface would be helpful. Just a note - to get the most out of your mix, screening is important. Al

Very cool, if a bit perplexing. Hard to fathom, for just one example, how the Keweenaw Peninsula of Michigan's Upper Peninsula could be in any but the highest category. That's a completely wild and unsettled region! And no, I'm not guessing-I've been there many times. All forested, all big white pines, hemlocks, and their many hardwood associates, to simplify. My point being, there's hardly any civilization there beyond a few very small towns, and the rest is heavy, native forest. Not to nitpick, but I can see other just as unexpected results all over that thing. All in all though, very cool. Just wish I could make out more of the print on the other ones. +oM