I water from the top. They sit in trays but there's never more than 1/8 inch of water from my regular watering. In addition I mist them daily when it's dry out, and not so much regularly. They sit in a tank, but there's no top on it. I have more outside the tank on racks that do well too, as the air here is naturally cool and humid. I'm trying to get more into growing heliamphora as it seems I have uniquely good conditions naturally all year round, and I believe in growing plants that you can provide good conditions easily for.