First Grow - Stardawgs from clones

Day 63 - 28 of Flower Changes this week include adding a 4th Maxibright 315w lamp and Agro bulb. I wanted to run 4 but originally could only afford to buy 3. These retail at £250 each per kit so theres now £1000 just in lighting. A huge improvement to overall light spread around the plants and more light penetrating the canopy to the lower bud sights. I've also spent the weekend insulating my space for 2 reasons. Obviously temperature fluctuations being one. I found the temps were anywhere between 17 and 31 degrees throughout a 24 hour cycle and wanted to get a more consistent day and night temperature. With the extra light it needs to be cooler too. 2nd reason was humidity. With the great British weather being as damp as it is the night time humidity has been over 75% some days which now we are deep into flower could quickly lead to bud rot. Insulating the space and running my exterior AC unit has now got that figure to below 56% at all times. I'm very happy with that. Feeding ratio remains unchanged this week. I'm going to continue running the PK13/14 for at least another 7 days or untill the buds finish fattening out. Still feeding 6 litres every other day. No further training at this point just pulling a few colas out of the way of the fan and one main cola from directly under a lamp as it was burning. Also stretch has now finished which is a massive relief as I've no headspace left in the tent at all. I didn't have time to take many photos of the buds in the dark but the ones I have put on show just how frosty these stardawgs get! Really living up to their name considering they are only half way through predicted flower time. The only further upgrade I would like at this point is a proper co2 with digital regulator. I have however read that they dont benefit much from extra co2 from this point onwards?? What is everyone's thoughts on that? Obviously I have my natural co2 generator and will leave it in untill the end of the grow. I realise I really underestimated the size of these plants and 6 sativa dominant species is a stupid idea. The tent is just too packed so on the next run I'll opt for less and go with a scrog. Thanks for checking in! I cant wait to see how the next week plays out.