18/6 - using 2 x 125 blue cfl's. Not sure of pH, but have fairly recently repotted using guano mix. The new growth is really healthy. The lower leaves are dropping off, i think because the potting soil I used originally was clearly rubbish... I'm only watering when it feels pretty dry now. Think I overwatered to begin with, so I'm holding back now. do you think it's just a sign of the damage done by using the crappy soil to begin with?
it is a possibility and that maybe you were watering to much which intern if you had nuts in the water, you would be nut burning them. Also i would invest in ph level for soil, get at lowes or home depot for like 8 bucks and then get ph lower at local hydro store. because right ph level omg the growth is insane so are the buds. hope that helped. and the crappy soil in a way can cause some probs with plant but not cause it to die off like that.
ok, that sounds pretty reasonable... I think you are probably right. So, besides getting a pH meter what else can i do? I'm presuming that since the new growth is good, if my nutes are right it shouldn't spread further up, right?
Yep. I looks like a good recovery. Stay where you are at in regards to your feeding. When you switch to flowering follow the nute directions to a "T". Don't try to add more, what it says is best. Good luck!