Originally Posted by Snook
In my experience, silica raises PH.
I do not argue the point about adding it first but I'd think that one should know how much silica, added before anything else, will raise the PH initially and then the addition of the nutes should bring PH back down to the working PH required. Am I F'dUp?
Any time you can land on your plants desired pH without having to alter the nutrient mixture with pH up/down tends to be a good thing.
I wouldn't rely on silica alone to adjust pH upward in all cases, I tend to keep it within the brands suggested application rates. I use DynaGro ProTeKt and tend to stay between 1.25 and 2.5ml/gal in my drain to waste grow, your product may suggest another range for whatever grow style you are using.
Originally Posted by beta
It's my understanding that precipitation is only a problem with concentrated nutrients. Once they are mixed into the reservoir at working strength they are no longer in danger of precipitation.
If you run a reservoir and pump where you are topping off a system with freshly mixed nutrient solution...precipitation should not occur.
When you are putting that top off mixture together silica should be first, followed by Calmag (if used), then base nutrients, then supplements, then pH the whole lot.