Adding more lights to a setup to promote more growth? and best yield techniques?

[kneegrow]

Hi guys i have 2 big buddha blue cheese in 11 litre pots and a 0.8x1.6 tent, i am using a 400watt hps light and they are at 18 inches away from the top of the plant, they temperature is usually around 25.27 sometimes slightly lower but not that much, the past week they have barely grew at all and im wondering if adding another 400watt hps light would help?

they are 11 inches from the top of the soil to the top of the plant and they are 5 weeks and 5 days old from seed, also id like to know with only have 2 plants in this space, what is the best option to create more yield? wether topping them or just leaving them im not sure?

thanks

 

[LEDBud]

I will suggest you try a Scrog grow with your two plants , you have a perfect size room for two scrogs really and it would or should maximize yield , not to mention keep you amused in the process.

Two lights would help you immensely , allowing you to lower the light to 12" or less (use fans) with out losing any light to the side area.

 

[c526]

I also feel the lights are 2 far away,bring them as close as heat will allow, if your system is on a fan/speed controller,turning it up allows the lights to be brought closer.
scrogg screens are a ton of work,and if you tend to get lazy(like I am) they can turn into a jungle,BUT there is zero dispute over harvest numbers

these are 400hps and I run my 600 only a little higher my scrogg is 40 inchx60inch 1 plant 2 lights

 

[LEDBud]

More wind under the lights would allow you to lower them more as well

Having a fan or two blowing at high speed over the tops of the plants and light will keep the leaves moving and heat down. A side benefit is the wind will speed up growth.
Your grow is looking real healthy , nice and thick !

 

[Stealthboat]

I think topping compared to doing nothing will usually result in a bigger yield, and a SCROG will probbly yield more than just topping those 2 plants. Plus it is kinda late in the game (week 5) for topping to work as well.