When should I cut the top off?

wait till they are about another 5 inchs or 3 nodes taller.

 

Don't. Topping is very old school. Much better low stress ways to get more tops in less time. Look up LST or SCROG.

 

It's a little too early to top but topping is a good method also never put more than 1 plant in a pot u got 3 in there you will run into some problems

 

Hell you got 3 plants in 1 pot for? You need to split them up like now. I dont top until I got 4-5 nodes (branches)

 

Lol I've seen people do 2 in one pot that's bad never 3

 

I have 24 in one pot and I haven't had any problems at all

 

Considering how close those 3 plants are to each other you probably are better off not topping. You don't have much side room there. Separate pots are usually worth using because you can move them away from each other to spread things out

 

I got an amazing yield from a papaya that I topped the first set of serrated leaves. Ok my cfl topped it for me but for shits and giggles I decided to stay with her. She grew what became 2 main colas. 4-5 oz from 150hps.

 

Way to early , wait until 4 weeks or atleast 4 nodes. Let it grow some leafs first.