When or how should I start training

Hey guys , quick question regarding defoliating / training, I’ve topped these girls above the 5th node , they’ve grown really bushy from the start, only about ten inches tall at the moment , wondering when and how I should start lst ? I’ve been banding and manipulating branches as long as they’ve been big enough to do so, just seems really congested in there should I maybe remove some of the fan leaves? Or just let them veg out until branches are long enough to tie down ? I don’t know if I had adequate lighting or it’s the strain or too much light but they’ve grown not even a foot high but are so thick lol
White rhino photoperiod
5 weeks old
Coco/ 40% perlite
Watering twice daily to run off , 500ppm canna coco range one watering , 300ppm r/o water with calmag every other watering ,
Fluctuating oh between 5.5-6.2 , but runoff oh still coming out at 7!? Have flushed previously but hasn’t changed, been that way since transplanting , I don’t think I rinsed my coco enough or buffered it wrong ?

Look up ‘supercrop’: that’s my preferred technique on photoperiod plants (assuming based on the fact you topped them).

Topping will force plant to grow out instead of up FYI. You can raise the lights or dim them down to let them ‘reach’ a bit if node spacing is too tight.

Only remove leaves if the health of the plant is at risk. Those leaves are producing the sugars you need to successfully flower out the plants.

Once a day is plenty. If you have to water twice a day it’s time to pot up.

You could probably bump this up to 650-700 ppm

How are you measuring PH? If a digital meter when did you calibrate it?