Yes, I stated that I'm not worried about the aluminum, all the same I won't use aluminum sulfate either. Although it may be safe, I worry about toxic levels. Just because lead is in all soils doesn't mean it's a good idea to add more. Same with aluminum. And if you mix turface without a mask, you will be exposed to it. As far as water absorption Axis noted that turface holds 95% of it's weight in water. Pumice only holds 15% and DE holds 142% Try diatomaceous earth in your tests. Optisorb is about the largest size available to home gardeners. Axis makes an excellent size, but is for commercial use only. Numerous studies document it's use as superior to most other amendments. Such as " Effects of diatomite on soil consistency limits and soil compactibility" by Ekrem Lutfi Aksakala, Ilker Anginb, , , and Taskin Oztasa Or "Effects of diatomite on soil physical properties" by the same authors. Also "Sustainable effects of diatomite on the growth criteria and phytochemical contents of Vicia faba plants." Mona M. Abdalla* Department of Botany, Faculty of Science, Ain Shams University, Cairo, Egypt. The Axis company also has great info on all amendments. As far as particle size, do a test. Fill a pot with sand, and one with gravel. Stick a pole in, and see which one gives more resistance. It seems to me gravel would. But I might be wrong? I don't know physics well enough to figure it out on paper. Ah and pumice is further dashed to the ground and called a fake, not a single user rises to defend. Well we can agree to disagree, my day job is a laboratory researcher,or was, I'm retired. If turface has various pore sizes then it is not very well made. Thanks for pointing that out. So you do not believe the manufacturer? Controlling pore size in fired clays is often accomplished with the use of polymers such as Polyethylene glycol. This process is extremely important to control how well purifiers work, or how well they hold up with the addition of salts. You are incorrect about the pore size. Yes pore sizes differs, but that process is used to make different products, and is very controlled. Turface is meant to have small pores size or it would ineffective in it's intended use. The porosity of fired clays is extremely important to have a consistent product such as fired brick used to built houses. Varying pore sizes will compromise the strength of the brick. Selling a product and manufacturing one are very different things. The pore size I reported is for calcinated clay. Range of pore sizes is from .1 -.01 microns. Median is .045 . Plants need a .2 micron minimum pore size to utilize. This info is from a study by Andreas Kalytta-Mewes, Kathrin Mattern, and Armin Reller University of Augsburg, Chair of Solid Body Chemistry Georg Armbruster Soil Laboratory. The pore analysis in the study was conducted by Quantachrome,Bavarian Institute of Applied Environmental Research and Applied Technology. Of course it appears none of these sources trump Al. Who has not provided any data at all to back his claims. Please prove to me that pore size is bigger, thinking Al is right because you sell clay products is not proof. After saying all this will turface work? Yes, it will. Works pretty good! Is it ideal? No, it's not, but what is? It's still worth trying for sure. It didn't work for me, but that means nothing. it has worked well for others. It would be nice if it allowed easier access to stored water, but it does store water, and air, and it lasts a long time, maybe 20 years. That's decent. It's a decent product, or appears to be. It would not be on the market if it didn't work. I know it's not meant for potted plants, but it is meant for grass. DE seems a better product, it has it's own problems. it is marketed though for plants more than ball fields, although it is marketed for that too. It's marketed for large commercial gardens. I use it in my garden. I use turface too for my grass, works well. Just not that well in pots for me. All i said that it didn't work for me. Sorry blame me, it's what you usually do when the mixes fail, you blame the poster. Many have said DE doesn't work for them. I actually believe them. All gardening is local. This post was edited by Drew51 on Mon, Dec 29, 14 at 15:33

Hi Al and others, I would appreciate advice on saving sick/dying Picea glauca, in pic.1, please. I bought it on post Xmas sale and it was ~50cm tall, looking healthy, with very bushy top. I repotted it without much root cleaning to keep most original soil with fungus, which I read Picea, like other pines, needs. I planted the rootball with old soil into gritty mix, mostly pine bark fines with seramice, with a bit of gravel, see in pic.2 very "gritty" indeed :); trunk is ~1/2" at the bottom). I used a biggish pot to let it grow freely for a year or two. I also cut the top to encourage lower branches growth but it never happened. Water it when the pot feels light, ~ weekly (it is early autumn here in Sydney) by bottom watering in a bucket, then drain well by keeping the pot at ~45 degrees for a while. Use diluted Nitrosol liquid plant food every two weeks. Keep it on sun for 2-3 hrs, then half shade. Despite all my care (or coz of it ? :), the picea never showed any new growth but started developing warning signs for last 2-3 weeks. Those few thin branches started dying. Their stem turns from brown to greyish-green and gets soggy before dying. See in pic 3&4, that branch in front which is dying now, with grey stem. Other branch died a few days ago. Only three normally looking branches are left. But I am afraid they are facing same fate. Anything I can do to rescue my future picea bonsai at all? Thanks and cheers, Sergey

Okay, I won't do the Diazanon, haha. Would be nice if there was a way to test for soil critters! We haven't had huge fluctuations, though it did go from a few weeks of nice hot weather (in the 80s at least every day) to a few weeks of coulds and some rain. There are no spider mites, I check both trees religiously. I also have my garden's wasp population check my trees out, and from what I understand they're predatory to other insects. The pH is 6.5. I was previously fertilizing every other week, but it has recently been so rainy that I haven't had to water, and thus haven't fertilized in a bit. I picked back up today (and then of course it rained). I'll keep an eye on it. It seems very happy in the pine nugget mix - at least the pine nuggets are better than cedar shavings. Someone did mention in my thread that pine nuggets are usually mostly pine bark, but not 100% so they can't actually call it pine bark - I am hoping that is the case.

You over-watered it. The root is damaged. When the weather gets cooler, a little extra water can kill a large plant. The safest way is using a "soil humidity meter". If the soil near the root center is wet, do not water.