How to thicken branches

Hey ya'll,

I need some suggestions. I've been feeding the girls the GH Flora Series. I've only been using the Micro and Bloom nutrients as suggested by my buddy at the local hydroponic store and the Lucas ratio. Each plant is getting about 6 to 9 gallons a week. I'm feeding every other watering. They're about a week and a half into bloom. I've decided to add cages, which I should have done two weeks ago, and I realized how thin the branches were because they broke kinda easily and the leaves felt thin. Is there something I should be adding along to GH? Why do you think the branches are thin? I've attached a photo for ya'll.

There is a decent amount of air flow so I don't think that's the issue. Thanks!

well lets start out with what strain you have and see if we can narrow it down between
Genetics
Environment
Nutrition

I have about 10 different strains and they all seem thin, so that'll probably rule out genetics.

What strain it looks nice and healthy. Armor si is a product by gh it a silica additive. Silica is supposed to strengthen and thicken stems and make a plant more resistant to heat. The stems don't look to small but it looks sativa dom with that stretch, the strecthier girls need support

shaking the plant (by hand or with wind) helps stimulate it to thicken up. Other than that, it's time. You can't get a month old plant to look like a 4 month old other than waiting. Also it's going to finish stretching in the next week or so and then focus on flowers. Proper light and a good amount of wind knocking it around (not too much of course). If they are all thin, then I'm guessing not enough light, not enough wind blowing through, or they just simply aren't old enough for what you are thinking they should be. Of course there could be things like over watering or other factors that would stunt growth.

did you use flora grow in veg

Okay thank you zchopper! I will definitely pick up some silica.

Well the plants were one foot clones when they were planted in the greenhouse on June 1st. So they're at least 2 months old. I'm not sure how old they were when we got them. When should I be concerned if the branches don't thicken up calico?

I'm hoping they'll thicken up after they're done stretching. I'm also concerned by the thin leaves though. Definitely too thin.

Yes hells I did use the grow formula during veg. Then I did some reading and learned about the Lucas ratio and learned it wasn't necessary so I stopped right around the beginning of flowering.

I believe they're getting enough light. We have polycarbonate panels on the ceiling. I also don't believe I'm overwatering. I let them dry out properly between each watering.

silica and potassium will help