Anyone using Silica (Potassium Silicate) as pH up?

[Animatey]

The best explanation for "add it first" that I've seen was one vendor that basically said "add it first by first adding to a smaller volume, diluting that to the proper pH, and then adding that to your reservoir". Somewhere along the way, I think the "dilute to proper pH" got left out by some vendors, and it got simplified to just "must add first" in common knowledge.

I've seen other forum posts that have said "add it first if you add cal-mag last, add it last if you add cal-mag first", since both silica and cal-mag products raise pH.

I've taken both of those to mean "add it whenever, just make sure pH doesn't go above ~7.5 each time you add a product (after the silica has been added". Then, I usually see about a 0.5 point drift up after 30-45 mins, so I just aim a bit lower for my "final" feed pH - i.e., what I measure right after I'm done mixing everything, without waiting for the silica to equilibrate.

This sounds about right to me.

I've been suddenly having tons of stunted plants this year though, probably 50% and I'm not sure what's up.... I thought silica would be a good choice since it helps relieve some kinds of plant stress, but I'm trying to rule out anything that might complicate things.

Since there is a chance it might do something negative, I will probably try a couple runs without it until I get everything straight again.

Thanks again for sharing your experience with it, I'm sure people will benefit from it and I'll definitely keep it in mind for the future.

 

[parsing_trees]

I use Pro-Tekt as a pH Up, to some extent. Once my plants are in flower, I tend to use a pretty consistent amount of Bloom (also Dyna-Gro), and can usually settle on the proportion where the amount of Pro-Tekt I use initially + the amount of Bloom ends up at a pH right where I want it for coco (5.8 - 6.0). I'm not opposed to adding a little Pro-Tekt after, though I add it in small amounts at a time and mix it in gradually. That would be adding roughly 1/4 tsp (1-2 ml) at a time to a 2 gallon (~8 liter) bucket, which seems to raise the pH by very roughly 0.3-0.4. I use pH test drops, so I don't have exact numbers, but yesterday it took adding 1/4 tsp twice to get from something a bit above 5.0 to around 5.8.