Light quistion

hey im new growing my first set using non hydroponics but a few high wattage lights and thas all however i started my flowering cycle real early to find out if it was a female or not and now that i know they are can i put my lights back to 18 hrs a day? or do i need to keep it at 12/12? they are bagseed plants and real scrawny looking things ill have pics of them up shortly ty

If they're just preflowering... then it should be fine... but if they are fully flowering... then I wouldn't do it because re-vegging tends to be EXTREMELY stressful on the plants.

just wait for preflowers or clone and flower the clones

too much stress could lead to hermaphing your plants