Silica

[DavidCampen]

Fumed silica is easy to get here. I thought of using that but I already had a bottle of Pro-Tekt.

http://www.multitechproducts.com/cab-o-sil-fumed-silica-aer-o-sil/?gclid=CLmJgd-GmcMCFcqVfgodjXkAbQ

 

[Bjorn]

Fumed silica is easy to get here. I thought of using that but I already had a bottle of Pro-Tekt.

http://www.multitechproducts.com/cab-o-sil-fumed-silica-aer-o-sil/?gclid=CLmJgd-GmcMCFcqVfgodjXkAbQ

Common mix-up, silica fume and fumed silica.oke:
I do it all the time myself, but google microsilica, its slightly different. But guess a hydrophilic fumed silica could do the trick as well

 

[DavidCampen]

Common mix-up, silica fume and fumed silica.oke:
I do it all the time myself, but google microsilica, its slightly different. But guess a hydrophilic fumed silica could do the trick as well

All the fumed silica that I have seen is hydrophilic. It will also have a smaller particle size and greater surface area than silica fume.
http://en.wikipedia.org/wiki/Silica_fume
http://en.wikipedia.org/wiki/Fumed_silica

 

[Bjorn]

You can get hydrophobic as well. It floats on water and is impossible to mix in. Surface is grafted with silane, while normal silica has hydroxyl groups.

 

[ALToronto]

David, the % of content listed on the Pro-Tek label is by weight. The molar mass of K2O is about 95, while for SiO2 it is 65. So those percentages must be divided by the respective molar masses to get the molar ratio.

The actual number is academic- I just wanted to point out that liquid silicates are not created equal.

For plants, I would be inclined to use organic sources of silica. I work with mineral silicates every day, and they don't really dissolve in pH-neutral water.

 

[Bjorn]

AlToronto, just use microsilica, its the next big in silicon fertilisation. Actually today field test have been done with it with great sucess. As microsilica, or silica fume as its commonly called is amorphous, it solubility is much better than mineral (quartz) sources. But still low that is true. If you want silica to be soluble at higher levels, then you must push pH above 9 and that causes problems.

 

[DavidCampen]

...
For plants, I would be inclined to use organic sources of silica. I work with mineral silicates every day, and they don't really dissolve in pH-neutral water.

I made a silica solution today using the procedure I mentioned above except this time I used a little over 9 grams of KH2PO4 and the resultant pH was below neutral, about 6.8. This 2 liters of solution was clear with no evidence of turbidity. From what I have read, the solubility of silica in pH neutral water at room temperature is around 100 - 200 ppm.