@Mañ'O'Green. Appreciate the comment. A google search of this concept leads me to a bunch of forums posts without data and websites with vague statements such as “may contain” or “might be a problem”. This is the issue in cannabis cultivation in general: lack of robust science. The only water tests of condensate I’ve seen so far came from questclimate.com/laboratory-test-condensate. Bottom line was even in cases where they did see some metal leaching, and it wasn’t in every test they ran, it was <100 PPB. Most US tap water exceeds that amount. Aluminum is known to be harmful when ingested so I’m all for not smoking it. But remember, its the soluble aluminum ion (Al+++) that creates the issue as it’s the only mobile form that plants take up. Aluminum itself makes up 7% of the earths crust so it’s basically ubiquitous. Since Al3+ ion is the issue for uptake and it is most heavily dependent on pH for its mobility and thus its accumulation in the plant, chemistry dictates that soil pH above 6.0 eliminates the concern. Well documented in soil Ag science and supported by basic chemistry. Ph buffering of soil is the solution most often employed to keep it out of plant tissues.
Really the only true answer is to measure the condensate, measure the soil change over time in Al3+ (not Mehlich3 Al), measure the pH of the soil over time, then finally measure the finished flower and leaf tissue for Al content. Thrown in some controls to boot and viola...publish that study! Would love to have the time to do that... but I don’t.
In light of all this, I’m inclined to believe that any small Al leaching off the condensate of my dehuey is really a non-issue as long as soil pH is greater than 6. I’ve measured my pH at 6.8 and have plenty of dolomite lime in my mix to buffer it.
Anyway, thanks for the comment. Sent me down a cool rabbit whole and hopefully provided some additional food for thought for people.
Finally, here’s a link to a soil testing company’s take on the whole issue if you want further explanation.
http://www.spectrumanalytic.com/support/library/ff/Soil_Aluminum_and_test_interpretation.htm
