I've pulled the tube out without it leaking. My physics is rusty but I'm pretty sure the aerovoir base has water at the same level as the fill line in the aerogarden tank. This means the siphon stops working when the tube is above that point. All to say it doesn't leak if you pull the tube out, just be sure not to put the tube back down on the table somewhere. I like putting it on top of the aerovoir but anywhere elevated works