Bottom watering is the recommended method. Top watering tends to cause shallow rooting of the plants and often isn't sufficient.

Just set the pot in a container of water for 20-30 mins (often less depending on the potting mix used) and let it soak up what it needs then remove it or dump the remaining water.

Dave

Some may find this article helpful in understanding why bottom watering, wicking, and capillary action can work well in very small containers (assuming good soil-less medium is used) but not work well in large containers.

https://gardening.stackexchange.com/questions/13774/what-is-a-perched-water-table

Dave

My container tomatoes are wet soil at the bottom and dry at the top, by water meter. Have I a problem?