Agree - edema. Since you're growing in pots, that makes things easy to adjust. First, leave them alone until the leaves droop just a tad. This is the driest state they should be in. Lift the pots a bit off the floor - your goal is not simply to pick them up, but to guage how heavy they are. After that, water them thoroughly, then lift again. You'll notice how heavy they are at this point. Wait a few days and pick them up again - are they as light as they were at their driest? If not, don't water yet. You'll want to go through several cycles of judging the weight to the point the leaves droop a bit before you have a good idea of how often they really need watering just by picking them up. Note that not all plants uptake water at the same rate, so don't plan on watering them all at the same time. You'll need to let each plant tell you individually when it needs water.