hey mate! Si is best applied in the soil/res' constantly at low levels,... Si does many good things, but for the benefits in the cell walls, it needs to be in consistent supply for best results,...
Foliar is great too, during veg' and early bloom is fine, but after that foliar isn't recommended unless really needed because of potential mold issues, and the pistils tend to die out when wetted down like that,.. My outdoor girls do this after rain, and foliar sprays,....
You will need a wetting agent, like Coco-Wet for all foliar application of whatever,... thses products take the surface tension put of the solution, so it coats and sticks better instead of just beading up,... Also, spray the tops
and bottoms of the leaves, there are more stomata located there... more surface area covered = more absorbed! ...best done during lights on, when the stomata are open for business, but if possible, remove then from direct blasting light.. slower drying helps more get in there, and there's a
remote chance of some mild burning,...
pH adjust to mid to low 6's, and best to use RO/Di water; less residue, less "competitive" access for uptake,... I highly recommend using humic-fulvic for the pot, and if you can find it, Ful-Power which is a pure fulvic liquid (BioAg),... read up on this, and chelation in the Reverence section and you'll see,... also a Si article/link there too,...
