Once you flush them wait til they dry out or need water. Once they need water i usually water slowly till i see a little runoff. Alot of people suggest putting your finger in about an inch and see if the soil is dry. Others suggest lift your pot after its watered and make a mental note of the weight then when the pot feels light then its time for water. I usually just chill out on watering til the plants leaves droop. Once they start drooping i water then usually a couple hours later they are perked right back up. I have no set schedule for watering. I let the plants tell me. There is also moisture meters you can buy but from what i hear they work ok. Some like them some hate them. Over time you will find out what works for you. So are you planning on using nutes? How far are they into flowering?