Hi :) I usually just look at the soil: if the top 5 cm of soil are dry, then I water. I also find it useful to "weight" the pot with your hands. Pick it up right after watering and then every time you check on the plant pick it up again.You'll soon learn how much your pot weights when the soil is dry and ready to water. Anyway, I grow outdoor and I water about every other day while flowering and once every 2-3 days during veg. It really depends on the weather for me