Dosage and Safety: Silica in Bonsai

I’ve felt compelled to start the testing and recommendations process, inspired by Ryan’s discussion of results. Blue Eden Calcium Silica and Carbon products are commonly popping up to the top of the recs I’ve been getting. I’m eager to see where this new nutrition model takes us but have a couple of questions for the community.

First, is there a dosage chart available for potted plants? Most of the Apical products seem tailored for larger-scale farming.

Second, regarding silica, is any personal protective gear necessary (I know that sounds silly)? I ask because, in situations involving materials with silica (e.g., cutting counter tops), protective equipment is used to prevent silicosis - basically the silica version of black lung disease. A member of my local bonsai club who grows commercially explained that his staff use PE when handling silica in hydroponic growing. Perhaps it is not an issue since we’re mixing these with water?

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About the safety part, any fine dust is dangerous especially inorganic. The same would apply to e.g, akadama dust. Work outside and or use appropriate protection.

Once the silica is in solution or suspension it should be safe to handle.

For the Apical recommendations I’ve gotten, the dosages are based off mixing a 50gallon batch. Here are the numbers I came up with for my coastal oak I tested most recently. I’ve done 2 rounds of this and am going to wait a little now to see what the tree does before another application OR I can retest. Am I doing it right? I think so. :woman_shrugging:t3:

I also included my product dose reference page too. Just copied from the labels on the containers


This is great! Thank you so much for sharing! It’s hard to unpack dosing on small trees😂

And regards to PPE for using the stuff, I don’t wear anything other than gloves, some of the stuff is sticky so I usually rinse my hands after mixing in each product. As long as it is in liquid form, you shouldn’t need respiratory protection. It doesn’t off gas much of anything and smells a bit soapy to me. I think it’s pretty benign.

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this is called “silica” but is actually not crystalline silica but some form of silicate salt that is capable of reacting with toxic metals to cause their removal? looks like it acts as a chelating agent in my view. look at the SDS you get with the product or pull one up on line to look at the hazards. from what I recall, looking at the bottle it is strongly alkaline and corrosive. just don’t get it on your skin. not a respiratory hazard in wet form. be careful when you spray it but likely not in high enough concentration to be a respiratory irritant as an aerosol.

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