Theres no way anyone can predict a watering schedule for you because there are too many variables, and not just medium and temperature, but humidity, lights, fans, size of container, and type of "soil," as well. The previous post got it right, you have just feel the soil to see if it is dry. If you are still unsure, try not watering them for a while until they just begin to droop...then water. This will give you some indication of how long you should wait between waterings, and a better feel for the soil. This will not hurt your plants if you experiment once or twice. Just be careful by keeping a close eye on them so they do not wilt too much. Keep in mind, most people tend to over water.