I'm using rebuildable clearomizers (not the Stardusts that you're using) and with proper maintenance (washing the wick and dry burning the head) I'm getting 10+ weeks before I toss them. As Katya mentioned it's best to buy rebuildable clearos. My tanks, except for cleaning and/ or changing the heads, have been going strong for almost 9 months now. As for your Riva it's an excellent PV. Also known as the Kgo which I own. Fires at 3.7 volts which is higher than the normal 3.3 volts from an eGo.
