how tall under 400w?

[Dboi87]

I typically use UBs 4 cola topping technique. What I was wondering is what you guys feel the max height I should let my plants get to when topping for four main colas under a 400w. I want to try to maximize my yield but I don't want them to get so tall that my light becomes insufficient. I'm sure the plant would do fine anyways and just drop its lower leaves but why waste the veg time just to drop the bottom leaves anyways?

 

[HeartlandHank]

I find that most plants stretch 2-4x. depending on the genetics. Some sativas though.. about 8-9x...

I would prbly put it in 4 tops at about 8inches, under a 400.

IMO, root mass is just as important as the actual height. a 14inch tall plant with small root mass at 12/12 will produce similar to a 8 inch tall plant with large root mass at 12/12.

You could also LST each of the 4 tops at 90deg angle, then flip.

 

[Dboi87]

Any tips on developing a strong root mass? I've seen plenty of products at the hydro store but it seems like most people are torn on cannabis specific products. Right now I've been using 5gal smart pots

 

[biostudent]

Any tips on developing a strong root mass? I've seen plenty of products at the hydro store but it seems like most people are torn on cannabis specific products. Right now I've been using 5gal smart pots

Indole-3-acetic aspartic acid, made in water solution at 100ppm and sprayed at the base of the plant causes rapid root growth in terms of girth in the Rosales order of flowering plants. You can purchase it on eBay or alibaba for a pretty reasonable price (10g for $15 maybe). It falls under the auxin class of plant hormones.