Plant has dropping, curling and yellow leaves. NEED HELP

Ok so about 2 weeks ago my friend gave me a plant to look after since his parents made him get rid of it. Problem is i really dont know what to do with it. I had it indoors for a while, but i dont think i had good enough lighting so i moved it outside a few days after some of the leaves (mainly the lower ones) started to wilt. The plant was healty and it is about 3' tall but now is not doing good at all. I dont have any pics right now but i will soon. I also wasnt very consistant with lighting at first but after about a week i put a timer on the lights for 12/12 like my friend had it at. Also could poor ventilation cause this problem?

I dont think its underwatering as the soil i still damp.

I was wondering if it could be a PH problem because i was watering it with "Ice Mountain" bottled water (yeah it sounds stupid)

I know its hard to help without pics but if any of this sounds like a common problem please help.

wow there is so many places to start. First of there might be to much magnesium in that water. Also might be enough nutes or to much nutes for that matter. There are so many things to say. Let me know when pics are up and I can help further. One more thing do not over water if your on a 12/12.
good luck

Depending on where you live and what your seasons are like, it could be easier to just replant it outside. Just be carefull about stressing the plant because you could wind up with a hermie after all your hard work.

Well i live in minnesota and right now it is very hot 80+ degrees and humid. at night it is about 60 degrees.

also i did not know you werent supposed to water on 12/12

The lighting outside from inside will probably stress the plant more.

Hold up. I didnt say dont water, I ment water one day untill you see water coming out the bottom then stop. then about 2 days later when the soil has started to dry then you water agian in the same method. But over watering is bad when budding in a 12/12 cycle. I did not mean to mess you up (sorry). A good way to tell if you need water after waiting a day or so it to stick you finger in the soil about an inch and see if on average if it is dry or wet and just use good judgement. Remember if you over water the roots dont want to grow and the better your roots the better your plant.

the soil has been damp since if got the plant, but i still watered it with 1 bottle every 4 days i would guess.