leave tips curling + moist soil?

My leaves have off and on been drooping slightly, not the whole fan leaf but just the last 1 - 2 cm on edges of leaves are curling under. I have been reading some threads on this and most people's advice is that they are drying out. BUT... my soil is still moist, the top layer is between 50/50 dark brown (damp) and light brown (dry), and within 1/2 inch down, all the soil is moist. I have been trying to let them dry out before i water them, however it is a bit difficult b/c I haven't bought a moisture meter and I am a little wary about sticking my fingers way down in there and scewing around (don't want to stress the roots out)

Any thoughts, or should I just keep reading different posts? (Which I will probably do regardless)

If your plants tips our curling it usually is your over watering your plants ... i would wait and water them until your soil is dry for 1 whole day to 2 whole days . Doing this will make your plant search for water growing the roots better . Then Water ur plants

Good Luck Growing

-HASH

Thanks for the advice, admittedly, I probably watered them too soon b/c it seems that the leaves get very dry and almost brittle, and I assumed that it was a watering problem. That got better after i watered and kept the soil from staying dry too long, but at the same time as I changed the watering, I also made a new light hood, moved the lights and added a fan blowing on them, so the leaf improvement could be any number of factors. thanks again, I think this time, I'm going to let it get dry down to a few inches( or more, anyone?) before I water. The dry leaf question is probably something else in it's own.
As for the roots, from the plants own history, I'm not too worried about them. i will be posting a different thread in newbie central after this, which goes into more detail about that.

next time you water, let it dry out for about 3 or 4 days. if your plants droop between then give them a light foilar feeding but try to water only once per week