Drew51 and sf rhino, thanks for the reminder! your correct we should not add this to a compost pile, I guess I will keep this in mind before I seriously consider using this. Here is a little work I done today, Polystyrene beads dry have a BD of 23.4 lb/ft3, I took 12ea. of these beads and soaked in water for 48 hrs and they weighed 0.7 g 12ea. of the dry beads weigh 0.4 g, do what you want with that I have nothing to compare that with since I don't have any granite or perlite at the moment. Something else I done was screened some calcined Diatomite over a 12 mesh screen, supplier was EP minerals Oil dry product BD of the +12 screenings were 21.4 lb/ft3 the -12 was 22.6 lb/ft3. I found tables on the net that says Crushed Granite is 97 lb/ft3, purposed substitute for granite is the poly beads. Turface MVP is 36 ñ 2 lb./ftó purposed substitute calcined Diatomite. I am posting some pics if I can figure this out, I have not figured out how to apply more then one pic per post so anyway here is the beads.

I struck out on finding the gypsum at Lowes : ( I felt fairly certain I could find it there. How annoying. I might be able to find it at this florist/small garden center, but I think that is unlikely. I'll try looking there anyway, since I have to run errands in that general area tomorrow. I did go ahead and use some gritty mix sans gypsum for some succulent cuttings, just to get them into something for now. Hopefully that won't be a terrible thing, but I figured succulents could tough it out for a while.

Hi, Kwie. We had a significant storm here & I've been w/o net service for a couple of days, or I'd have responded sooner. Come to find out, though, the cause was a bad modem & not the storm. Hint - place a higher value on the opinions of those that have actually USED the gritty mix to implement the concept that the more water held inside of soil particles and the less water held between particles, the better are your plants' chances to realize their genetic potential. Many growers simply announce they really don't understand the concept when they say that the gritty mix doesn't hold enough water. ..... and I'm not singling any one person out - only noting that because the gritty mix is so widely adjustable for water retention by varying the ratio of screened Turface:grit, it can be made so it holds a significant amount of water, yet no (or very little) perched water; so if it doesn't hold enough water at a 1:1:1 (or 3:3:3) bark:Turface:grit ratio, simply change to 3:4:2 bark:Turface:grit for more water retention. The bark's water holding ability is somewhere near the average of equal volumes of Turface + grit, so it is a good light weight and inexpensive way to bulk up the soil, provide a little nutrition, and ease the apprehension of those who are uneasy about growing in an entirely inorganic mix. The idea that only soils that are 'rich and black' can provide a healthy home for roots is deeply ingrained, even if completely false. Structure is the most important aspect of soil function, not its ability to feed the plant. Nutrition is monkey easy and on the grower's shoulders - or should be. 1) The gritty mix uses a limited volume of organic matter to ensure the soil cannot collapse. If you used only 2 components, like bark and Turface, you would have either too much water retention (for most apps), or too large of an organic fraction, which could clog the soil over time as the bark breaks down. You CAN use only Turface and grit if you like, but I would suggest you start at a 2:1 ratio of grit:screened Turface. Foliage-Pro 9-3-6 has everything in it that plants need, and super-simplifies the growing experience - makes it really hard to go wrong. 2) Grower size Gran-I-Grit and #2 cherrystone come prescreened, but I still give them a quick screen over insect screen to rid the grit of the dust ..... or I use a kitchen strainer and rinse it off. It's not much extra effort, and prevents any sludge build-up on the pot bottom. I also rinse until the water runs clear out of the drain hole when I first plant in fresh soil, for the same reason. Everything but the dust gets used. Screening is important because particles of roughly the same size don't compact. Think of a jar of marbles and a jar of BBs. Mix the BBs with the marbles and a good part of your air apace disappears. Mix in sand, and almost all of it disappears and the soil starts to hold perched water, which is the limiting factor the gritty mix is aimed at eliminating. 3) The finger test works if your pot diameter is large enough and the planting is established. If you give a little thought to your watering intervals, it's hard to over-water anything in the gritty mix. I water my succulents on the same schedule as all my other plants and never have a problem. I rarely 'test' to see if the soil is moist - after a little while, you'll develop a feel for when plants need watering. You only need 1 skewer or dowel if you use that method until you get a feel for things. Just wipe it dry with a paper towel or rag between tests. The reason many of us use 2 different soils is more a matter of $, effort (the 5:1:1 is easy, the gritty is more effort but a better end product), and how long a plant will go between repots. All my veggies and garden display containers that go on the compost pile in Oct get 5:1:1. All my long term plantings (2 or more growth cycles in the same soil) get the gritty mix. A few fast growers that would normally go in the gritty mix (hibiscus, datura, brugmansia, ....) also go in the 5:1:1 because root growth is so vigorous they need repotting every year if you want the most out of them. Anything else you can think of? Al

I've never tried AVs side by side in gritty and 5:1:1, so I can't say. They should be pretty easy and happy in the 5:1:1 though. If I wanted to grow the very best AV I could produce, and had to choose only one soil, I'm not sure which I'd choose. If I chose the 5:1:1, I think my decision would be influenced more by what everyone else uses (it's closer to media labeled "AV soils"), rather than what I already know works well for the plant. I think, if someone is trying for the first time in either the 5:1:1 or gritty mix, the 5:1:1 would be the easier choice, but I can't say one or the other has more potential. I think its pretty accurate to say 5:1:1 for annuals and gritty for perennials, as long as we know there will be some exceptions - particularly when we have fast-growing perennials or plants with naturally vigorous root systems; those, we might want to consider putting in the 5:1:1 mix - especially when a yearly full repot is in the plant's best interest. Al