Not letting your plants rest...ehh...thats a thing I wouldn't do myself. At most, 18/6.

Any plant can only absorb so much energy from light throughout the day. It utilizes that energy when the lights go out. You could leave the lights on 24/7,and watch it crawl along...or introduce a dark period and begin seeing the results of significant growth that occurs while its in the dark.

That and it'll give your space time to cool down eh.