Different plants need different amounts of water. Where you place them matters, too. They may dry out faster in direct sunlight and in a warm area. Generally, many plants need more water in the warmer summer than the colder winter. Not sure if a plant needs water? Try the thumb test: if the soil in the pot sticks to your thumb, you don’t need to water.
Remember to remove dust so the plants can absorb light properly. Spray a mist of lukewarm water on smaller leaves or use a soft damp cloth on broad ones.
IKEA plants usually have enough fertiliser for 1–3 months. After this, it can be good to add some every month during the peak growing cycle.