Personally I find autos grow their best with 20 hours of light , 4 hours of lights off. I've grown em under 24 hours light and found yield doesn't increase just finish a bit quicker.... and definitely not worth the extra hydro all grow for 5 days faster lol. Considering Uve had it on 18/6 and shes now cozy. I wouldn't disrupt her light cycle and throw her for a loop. A longer lights on cycle is something u start from the word go. Cheers!