First grow - RQS Royal Dwarf

Feel so close to the end, but with that comes a level of anxiety that something will go wrong! The night time temps have really dropped. I'm relying on the 4 walls of the shed, the 200w HPS lamp and an electric heater. Day time temps around 19-20°c, night time temps between 15°-16°c, thanks to the light and heater. Also relying on the hardy characteristics of the ruderalis strain to cope with the suboptimal temperatures.. Looking slightly droopy this evening and I feel like there has been little growth in the last few days. I think (emphasis on 'think') that it's thirsty. As a newbie, it's really just a guessing game from what I've read, and gut instinct. Pot didn't feel particularly light, but I have good draining soil. Also the leaves are dropping, rather than curling in on themselves; suggestive of underwatering, rather than overwatering. Fed it with 750mls, supplemented with Biosys (half scoop) biobloom (0.5mls) and topmax (0.5mls). Fingers crossed I made the correct judgement. Plenty of flowers ready to grow. Just hope temps don't drop too low and stop the grow completely. Thanks for reading. Please comment with any thoughts or ideas. Would appreciate the support where possible :) 25/10 - So I was right in thinking it was underwatered. A good watering brought life to the plant again :) Wanted to lower my light yesterday but was restricted by the main stem. I tried some gentle LST but ended up super cropping by accident. Appears to have done it some good. The leaves and stems have not drooped and are all now facing the light. The canopy is much more even which is great. I've decided to switch to the 600w LED board during the day... And then back to the 200w HPS lamp over night. Doing this for several reasons... To expose the light to different waves of the spectrum, to reduce costs and to benefit from the heat of HPS when the temps are lower at night. So far so good. Enjoying seeing the development of the buds :)