Relative Humidity, how low can I get away with?

Just went to turn the AC off and open the screen door, it's 70% outside at 9:45pm so that's better than too little RH I guess, right :/ I think I need to invest in a proper dehumidifier, but I'm concerned about the heat it will give off when operating. I've seen one that's 90 watt, is that I good idea for the room where the tent is located?

Low humidity levels aren't ideal but should be fine as long as you keep up with the increased watering needs that the plants will have. In the winter where I live my humidity levels typically hover between 30%-40% for the whole grow and I have 0 issues with my grows. Temps are a little high, however. Ideally, you would want your temps under 82F to prevent the plants from getting stressed from the heat. If you cant manage to bring the heat down, it might be a good idea to look for strains that specifically thrive in hotter environments.

Bonjour je te conseil de prendre des variétés qui sont très résistante a l’humidité comme les sativa originairement elle vienne des pays chaud tropicaux et humide mais je vous préviens la sativa sera toujours plus longue que l'indica mais vous n'aurez plus ce problème.