Let the soil dry out before watering.
Lift the pot, and if it feels heavy then it probably can go a few more days without water. If the pot is really light then you should water it.
Do you PH your water?
Are you using liquid fertilizers?
What kind of soil are they in?
Tell us about your...
That first leaf looks like it symptoms of Ph fluctuations, and possibly magnesium. Your plant looks pretty healthy in those last pictures, so I would not worry about it too much.
*Check the ph of the runoff water if you keep loosing leaves*...
Looks like symptoms of Ph fluctuations...
Quick Summary: Managing pH is crucial for cannabis plants to be able to take up nutrients through their roots. When the pH around the roots jumps up and down, it can stress the plant and cause brown spots to appear on the leaves. Spotting on the leaves...