12.0v LED strip effectiveness

Save your money, they won't do bugger all. Also, if you do use them, plants need light from above, side lighting is useless.

Well, if you are thinking energy wise you would have to leave that thing on for days to just use 1Kwh Idk how much Electricity is where you are but 57c for a extra bit of light sounds like a smart move to me. Anything that helps your overall ppfd. I even have messed around with cheap 10watt led bars, did they add anything to it, sure y not. Did they take anything away, nah. And for the cost per Kwh just add me to the lower side of the canopy to get with light pen if you have a weak light. Good luck pal

actually you might be better off with using 1 13w philips led bulb at this stage with your original purple lights. 2-3 standard led bulbs can get you through veg and 3-4 can easily flower a single plant. you just pop the diffusers off and you got yourself a led puck. if nothing else is available this is a viable option to grow under and keep them at 25cm from the plant. you can supplement with these led bulbs even when its on your balcony because i dont know how much direct sunlight it’ll receive on your balcony and anything under 6-7 hours will be kinda disappointing in the end so if you can supplement with a couple of 13w led bulbs for domestic use with the diffusers popped off you’ll get better yields in the end. as for the led strip, i mean your plant seems like its not stretching atm so your purple lights are doing an ok job at providing the bare minimum for this stage but you’ll need to provide more lights soon either natural sunlight or as i meantioned some home use led bulbs can get the job done as well. peace!