Potassium bicarbonate or Potassium silica?

I will be using potassium bicarbonate or potassium silica for ph buffering in RO water. Is one better than the other for what I have in mind?
Why would you choose one over the other

Id use potassium silicate just for the benefit of silica

silicate, but don't go mad with it. soda bad

Silicate is allsoo bad if you put too much.

Thank you for the replies. I find the silicate interesting but have definitely come across numerous warnings about overuse.

It helps make strong plants but overuse makes brittle stalk

Silicate precipitates in too high concentration.

I think Agsil sounds like what I would be looking for. Build a soil says to use 1.5 grams per gallon to buffer RO water.

An off topic question.
If I add RO water buffered with Agsil would I still need to add calmag if it is going into supersoil that already has Dolomite and epsom salt in it?