Water them moderately and during the growing season plant food once every two weeks.
It will be clear that not all plants have the same moisture absorption. Never water when the soil is still wet.
Treat the house plants with a spray from the plant sprayer and put them outside during a mild rain shower. As with humans, plants can get sick, an important reason is often that too much water is given, so do not indiscriminately the same amount of water to every plant.