Anyone using Silica (Potassium Silicate) as pH up?

[Animatey]

I have pH up and Pro-TeKt on hand.

I'm using RO water, so after adding nutrients I need to raise the pH.

Does anyone use something like Armor Si, or Pro-TeKt, or Silica Blast etc... instead of pH up?

I wonder if it has the same buffering capacity etc.

Thanks for reading.

 

[Suki]

@Bruce Campbell

 

[Bruce Campbell]

Yeah - I use Bloom City Silica Boost as my pH up. It's a fulvic-acid complexed potassium silicate, like other Si boosters.

I add it last and use anywhere from 2-8 mL/gal (as needed) to raise my final feed pH from around 5.2-5.8 to about 6.0-6.2.

If you're pre-mixing feed or mixing up a reservoir for automated feeding, it may have different long-term stability / pH drift characteristics than pH Up products. But, I use my feed right away and haven't noticed any problems.

Si compounds can react with calcium to form insoluble precipitates, but I think that's mainly at high pH levels (~7.5-8.5). As your soil dries out between waterings, Si boosters may have a larger impact on soil pH and nutrient availability than pH Up products. But, I grow in peat and normally keep my containers above about 50% wet.

 

[Animatey]

Yeah - I use Bloom City Silica Boost as my pH up. It's a fulvic-acid complexed potassium silicate, like other Si boosters.

I add it last and use anywhere from 2-8 mL/gal (as needed) to raise my final feed pH from around 5.2-5.8 to about 6.0-6.2.

If you're pre-mixing feed or mixing up a reservoir for automated feeding, it may have different long-term stability / pH drift characteristics than pH Up products. But, I use my feed right away and haven't noticed any problems.

Si compounds can react with calcium to form insoluble precipitates, but I think that's mainly at high pH levels (~7.5-8.5). As your soil dries out between waterings, Si boosters may have a larger impact on soil pH and nutrient availability than pH Up products. But, I grow in peat and normally keep my containers above about 50% wet.

Thanks for taking the time to reply!

I appreciate you taking a break from slaying armies of the (un)dead

 

[Mizzo81]

I’m pretty sure if you’re adding silica it should be added first and allowed some time to “bond” to the water not sure that’s the correct wording. If not it can make your calcium almost coated and harder to uptake. @Mañ'O'Green can explain much better.

 

[JP1]

I thought of doing this since I've heard of it before but @Mañ'O'Green also advised me that the silica has to be mixed 1st and let set. I have noticed a lot less sediment in my tank since I switched to his order of operations

 

[Mañ'O'Green]

I’m pretty sure if you’re adding silica it should be added first and allowed some time to “bond” to the water not sure that’s the correct wording. If not it can make your calcium almost coated and harder to uptake. @Mañ'O'Green can explain much better.

Yes that is correct Silica first and time to bond to the water.

 

[JP1]

The Athena nutes actually say to use silica as the pH down but to add it 1st. So I'm gonna see how stable they are and then try to figure out the pH adjustment for the silica and then add it 1st. But honestly that seems like a lot of science for me to unrealistically do. So I might attempt it but I'll most likely stick to the orange bottle

 

[Animatey]

The Athena nutes actually say to use silica as the pH down but to add it 1st. So I'm gonna see how stable they are and then try to figure out the pH adjustment for the silica and then add it 1st. But honestly that seems like a lot of science for me to unrealistically do. So I might attempt it but I'll most likely stick to the orange bottle

Yeah if I have to add it first and let it sit, I'm not going to use it. I need to keep things a bit simpler than that. I'll just buffer with tap or pH up.

 

[Bruce Campbell]

Yeah if I have to add it first and let it sit, I'm not going to use it. I need to keep things a bit simpler than that. I'll just buffer with tap or pH up.

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.