start of new grow few questions?

So i've started another grow and this time opting for less plants bigger pots. The pits are 15 liter and i have 15 cuttings. My tent is 1.2 x 2.4 x 2 there about 6"intake and extractor with carbon filter. 4 x 6" osculating fans. Upon potting the cuttings in Terra soil from B&Q i had only 1 x 600 w light at 50% raised high for a couple of days to allow cuttings to get used to new conditions. After 5 days i lowered the light and added a second light in there dint look to be enough light covering the area. So i now have two 600 w majority of the cheese cutting are looking great few have slight burnt tips but i think this is just down to new soil etc. I have been feeding with rhizotonic and ph between 6.0 7.0. I have also given canna a and b two days ago at full strength which i know is probably too early. I plan to give the plants a good flush through with plain water under the tap in bath to try to balance the nutes while it is still possible to move them in and out of tent. Would it be ok to flush like this one time to balance the plants? Also i think it would be best if add another light soon as having even two lights low i feel some of the outer plants are not getting enough light... Currently the heat is around 30 degrees but i will be able to drop this massively as i am currently extracting into same room as intake but i am waiting on a venting cover i can insert nicely into partition wall and vent into another room hope fully i will have this done in a couple days.

i also plan to top the plants and defoil the lower parts to encourage maximum energy being sent to the colas.

What are your thoughts on the above?

Looking for any suggestions to make this a success.

I would hope to get around 40oz would you say this is a reasonable target?

is there anything anybody would suggest i do?

Thanks again.