I emailed GH and they responded this:
“Armor Si is going through the registration process in Canada as we speak, but unfortunately do not have a timeframe for it to return to shelves. Until Health Canada approves our registration, it will continue to be unavailable as a result. Once the product is available again, it will be at retail dealer sites across the country.”
all remaining stock in Canada will remain on shelves until sold. Like others have said it is available on Amazon.ca for about $50 shipped. Some have had success getting it in the country thru Amazon.com but it’s hit or miss.
As for a 1:1 replacement the closest I’ve found is Optimum Hydroponix Silicate. It’s a Canadian brand at $10/L it’s 0-0-3 it has (3% K2O) soluble potash derived from potassium silicate and (8% SiO2) silicone dioxide derived from potassium silicate
GH Armor Si is 0-0-4 (4%K2O)
and (10% SiO2) both derived from potassium silicate.
Optimum Hydroponix® Silicate is an easy to use liquid formulation of potassium silicate (K2Si) to provide supplemental silicon and potassium.
www.hydroponix.com
I’m sure at 1-1.5ml per gal it would be fine. From my understanding Silica is one of the rare supplements that cannabis will not get toxicity from.
Hope this helps