I have 2 silver bullets. Have one for over 4 years. They are great. And stand the test of time. I use mine at 6 volts only. I know. Shame shame.lol. to answer ur question I have not. Guess I never felt the need to. I wouldn't recommend it though as you won't have any airflow then on allot of tanks that have the air holes right above the 510 threading.