The N. ventricosa is super hardy compared to many other neps. N. alata and N. Judith Finn (a hybrid of N. spathulata and N. veitchii) are also pretty hardy. I grow my N. ventricosa outside during the summer hanging from the branch of my apple tree. It gets a bit of dappled sun through the leaves and a lot of indirect sun. It handles temps from 40°F and into the low 90°s with no problem. My humidity can get down to 15% RH, but is usually between 25% and 35%. I top water them and keep the soil moist.