diatomaceous earth, how much to use

I looked it up a bit. It said for foliar spray use about 4 tbs food grade de per gallon of water or dust a bunch on top of soil for insects. But i want to know how much to mix in my soil mix and how much is needed to add a good source of silica and if the foliar application will provide silica. Also calcium will this take care of my calcium needs in soil/soilless with ro water, will i still need cal mag?
@whitebb2727 you use the stuff right?

Diatomaceous earth will not handle calcium needs, but it will handle your silica need. I used to use it but have since phased it out in favor of oyster shells since they contain calcium in addition to silica. Most DTE is like 80-90% silica, alumia, and iron with some other trace elements, right? Foliars of DTE don't seem to provide silica since silica is primarily absorbed through the roots.

Try mixing in crushed oyster shells (if you're in Washington, take a day trip out to Willapa bay. I pulled up to some random mountain sized pile of shells in a podunk town out there, filled my pickup bed, went to the beach and got fish & chips, then drove back to Olympia) for your calcium/silica needs. A soil with decent compost composition should not need magnesium, but I've found bad compost can be call for an epsom salt foliar. Most cal/mag products put in way too much magnesium. Plants don't really experience magnesium toxicity, but you don't need as much as the nutrient industry would have you believe.

Just sprinkle some on top layer of your pots; enough to cover most of the surface area around the base of your plants stems. Don't bother using it as a folar spray. You can put it in your mix globally but it's not as effective that way to prevent pests like gnats. I use about a handful on each 10g container; figure a palm sized pile is about 3/4 cup; doesn't have to be an exact amount. I also agree that oyster flour is a much better source of calcium and it helps regulate ph but it also takes awhile to become available so if you are using a very fresh mix that has not been amended & recycled a few times it might be good to add a liquid organic cal/mag if your water source is RO or distilled. All you need is 10 drops per gal and after awhile you might not even need it to add it at all. DE is a good source of silica but it also needs time for the microherd to break it down to become useful.

Food grade is a must. Two types of DE. Amorphous and Crystalline. Crystalline is much smaller and harmful on lungs of your animals and you. Fertrell is the brand I use which is amorphous and is mined from deposits that don't contain high amounts of heavy metals. Many feed stores carry this for animal mineral consumption. Three grades essentially......pool filter grade, feed grade and food grade but in reality there is also the type from home depot which is amphorous but is not food grade and is used as an insectide (safer,concern) which would leave one to believe it is considered feed grade and may contain heavy metals.

http://www.fertrell.com/diatomaceousearth.htm

Thanks y'all. I am going to mix in compost as i recyle and re amend. I will try to add the oyster shell too. I crush my own rocks and i got a food grade de; very important , i think i could use feed grade but won't risk it. Now if olnly i hadn't started my mix with so much perlite ,oh well a little paste shouldn't hurt right? I switched to pumice and want to use straight lava rocks. Ok good daze.

esh dov ets said:

Thanks y'all. I am going to mix in compost as i recyle and re amend. I will try to add the oyster shell too. I crush my own rocks and i got a food grade de; very important , i think i could use feed grade but won't risk it. Now if olnly i hadn't started my mix with so much perlite ,oh well a little paste shouldn't hurt right? I switched to pumice and want to use straight lava rocks. Ok good daze.

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didn't breath the dust, bad shit.