MichiganMedGrower
Well-Known Member
I must of had a bad batch of promix hp...mine was at 5.4-5.5 last run...i added some extra lime this run...
Don't forget that runoff is not accurate as a need to know at the moment the exact root ph.
Slurry soil test or expensive meter is the only way.
It is more effectively used to monitor trends. As the ppm of salts in the pots rise and build up the ph will show lower in the runoff even while plants are uptaking too much nutes and burning for example.
This would mean root ph is in range as they are eating and that only the runoff with the extra dissolved salts is showing low ph.
I read this tip on the pro mix (premier horticulture) website in the education section.
So when I start to see high runoff they are likely eating what I fertilize and if it starts showing low I likely have salts building up.
I have recently added lime to my soil but for the calcium not ph control. My well water has gone softer with the drought this summer. But pro mix also warns to check all batches for over liming. So I am careful not to add too much in addition to my water or I will have problems over time as the calcium builds up in the pot.
I don't know where in all these articles and videos the lime one is but even though there is no cannabis info this site taught me many things.
The most important being about alkalinity and fertilization.
Sorry for the long post. I am high as a kite right now.
But here is the link.
http://www.pthorticulture.com/en/training-center/