
Rockwool vs. Perlite vs. Hydroton vs. Soil - namidark
http://hydronerd.com/2014/10/rockwool-vs-perlite-vs-hydroton-vs-soil/
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nkurz
Nice comparison, but I think he missed the best option: Diatomaceous Earth
(frequently abbreviated DE). It's been used for Bonsai for a while, but some
tomato growers have been excited by it for a few years now:
[http://www.tomatoville.com/showthread.php?t=22329](http://www.tomatoville.com/showthread.php?t=22329)

I used it this year, and think it's great. Ph neutral, sterile, cheap, non-
hazardous, holds water but allows oxygenation, low environmental impact,
pleasant to work with, and locally available. It can be purchased from chain
auto parts stores as an oil spill cleanup
([http://www.oreillyauto.com/site/c/detail/MTA4/8925/N0431.oap](http://www.oreillyauto.com/site/c/detail/MTA4/8925/N0431.oap))
and sometimes from Dollar Stores as kitty litter.

Well worth trying if you are starting seeds or rooting seedlings. If buying
for the first time, note that you do _not_ want "food grade" DE, which is a
fine powder. The seedling stuff is more like fine grained cat litter. And you
want to be sure you aren't buying a clay product instead, since some have
similar names. Ultrasorb, Optisorb, or Blue Ribbon DE Premium Cat litter are
brands to look for --- make sure it explicitly says "diatomaceous earth" or
DE.

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kolev
How about nutrition profiles? We've seen huge vegetables and fruits at the
super markets, but their profiles suck compared to conventionally-grown, but
usually smaller plants. If we only focus on rapidly growing biomass sold per
weight ignoring the main reason we need plants - their nutritional benefit,
we're going nowhere. Also, we know from some research that the more a plant
has so struggle, the better its micronutrient profile is. Such example is the
connection between grapes, climate, and resveratrol content.

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unclebunkers
I was aware grapes having a higher percentage of tannins, flavenoids, etc...
when grown in adverse conditions. However, I thought this was a property of
the fact that the plant always commented the same nutrients to the grape, but
because it's restricted in how much water it can intake, the grapes never
fully plump with as much water. This plumping would reduce the percentage, and
then dilute the wine. I didn't realize they actually provide more nutrients.
This seems counter intuitive, since the plant would on rocky hard soils, have
much fewer nutrients to draw from. Do you have a citation handy, it would be a
good Sunday afternoon read?

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kolev
I remember reading (maybe here) about a guy who did hydroponics and comparing
nutritional profiles and got better results for certain nutrients compared to
conventionally grown ones. I've read long ago resveratrol especially
discussing the content in different regions and grape types across in Europe
and also why Muscadine grape (native to Florida) has the highest amounts - few
times higher than Spanish reds. I think Oregon is also better suited for
healthier wines as well. I don't have anything handy, unfortunately as I have
the bad habit not to organize my findings outside of keeping the conclusions
read or made in my head, but those reads made me switch to Spanish Rioja from
French Pinot Noir. I never looked at the map before now, but it seems that
Rioja's location is very well-situated for higher resveratrol and the wine is
great. :)

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sergers
If I needed a medium to nurture root structure a and retain some water/air,
coconut coir all the way

