If the water is being bubbled or peroxide being added then I guess it would be alright to water from the bottom. But imo watering from the top gets more oxygen to the roots. It's also easier.im using 4 gallon buckets and i am looking for ways you guys use to water. some people say to use the old school way of pouring over the top and some say to put water in a bucket and lower the pot into it so it sucks water up the bottom.