No. I tried Dr. Tim's one and only and the aqua balls. I'm telling you Elliots these things are amazing!!!! They do much more than cycling. Tank is crystal clear and water parameters are perfect.. As a test I put 4 ppm of ammonia in a 75 gallon tank-- I dropped 7 balls in my aqua clear 110. Within 15 minutes I had no ammonia no nitrites... There is no product out there that will compare to this period!