From OSA28 website:
Countless studies show silicic acid affecting plant structure. It's one of the most visible and quickest effects growers report. Silicic acid builds more rigid and compact cells. It also helps convert more nitrates into proteins, which impacts node spacing and increases flowering sites.
"Double dose by root or foliar to reduce stretching in early bloom"
Well then.... One of us is wrong and I don't think it's me... soooo.
I do! How do I know? Over 40 years of growing helps. All my life on growing anything else, I grew up on a farm. I farm in my retirement (organic) and my jobs have all been in growing - Actually running the facilities!
I don't have to spell it out as Flowki did a bang up job on that!
If your in soil. The plant gets all the Si it needs from the soil. Hydro plants don't "need" to be supplemented with it but, it's not a bad idea....Besides proper
quality hydro nutrients. Contain all you'll need...
Si will help regulate P uptake, a bit... Helps with drought tolerance, a bit. Makes for stronger cell walls (in hydro use), a bit more..... It's said to "irritate" the plant into creating more trich's. Ok but, other things do that better, and do more for the plant in other ways too. Far better to use a sulfate like, potassium sulfate and/or Magnesium sulfate. Don't forget Manganese sulfate. That will increase plant potency
but, there are many things you need to know about it's use and it's relationship with other minerals. Not so much with the Mg and K sulfates.
Adding Si to feed solutions, needs to be done in a particular order or it will react with Ca and form a precipitate that voids (locks out) the availability of each.....Not to mention it will have effect on pH over time.....in soil..... I don't even like the Si family in pH up products! I don't use it other then what my soils may get from added garden gypsum..
There are many things said to "help" the stretch. Most are wive's tales or simply do little. In other words, I haven't found anything that has a profound effect on decreasing the stretch. Running your MH bulb for the first 2 weeks does little but, maybe the thing that has any "real" effect. Minor but, effect nonetheless.
The best way to control the stretch? Don't veg them too long! Flip them at the right height to start with...considering how much they will stretch....
"Problem" solved before it starts...