I'm using a soil medium...and its so easy to over water my plants. Why can hydro grown plant roots just sit in 100 percent water, alllll the time and not become over watered?..
the roots need oxygen, where as the top of the plant need CO2. in soil, when you water the plant all the available space is taken up by the water, then as the water evaporates and is absorbed by the plant, it causes a vacuum and pulls fresh air into the soil. if you over water, this process can't happen quick enough so the roots start to rot from lack of oxygen. in hydro, you are oxygenating the water by using an air pump, so the roots are getting enough oxygen even though they are submerged in water.
That is a good explanation flarkington. That is why it is a good idea for some people to chose that way to grow instead on the soil route. If you have trouble with constantly overwatering, then maybe you should look into that. Just pay attention to the amount of water in the soil and dont water unless the soil is dry a couple of inches down....that is any easy way to check if your plant needs watering