First Grow Lighting/Speed Question

This is my first time growing and i just have a couple questions. I have three plants going which I started the first week in may. I am going out of town for awhile in august, however, and would like to be able to harvest before then. I was wondering if during the vegetative state you can keep lights on it almost 24 hrs to increase growth speed, then switch later to the 12/12 cycle. If so, then how big should I let the plants get before switching to this cycle? Thanks.

You can initiate flowering anytime after you have 4 - 5 nodes. Most people recomend 18/6 lighting for vegetative growth. About the time, it really depends on your strain, if it's a indica-dominant strain (short & bushy plant, body stone) the flowering time is usually 7 - 9 weeks. For staiva-dominant strains (taller & lanky plants, mental high) flowering time can be up to 12 weeks. If you've bought your seeds from a seed bank that info should come with the seeds. If they're bagseeds the only way to tell is by the characteristics of the smoke (stoned vs. high) and how the plants look. However remmember, each strain is unique, those are just generalities.They should be ready to start flowering within a couple weeks. I am currently growing an indica strain which had 8 nodes after 6 weeks and was plenty ready for flowering. If possible get someone who you trust your life with (seriously) to look after them when you go away. If not, try to start flowering to give them enough time to finish their flowering cycle. If you can post some pics someone can help tell you whether it's indica or sativa.

*note - If any of my information is incorrect, please post a correction. This is based off my memory, and I don't want to give out bad info.

oh, and good luck

Thanks thats very helpful. I got the seeds from some website in Canada awhile ago, they say C99xA11 if anyone knows which strain/strains that is. Ill try to take some pictures too once they really get going.