I stopped using bio balls years ago and there seems to be a huge difference in the long term stability of the params. I dont even use LR in the sump, the only thing in there is the heater and skimmer with some cheato and a light. All my filtration is done with a good skimmer, a good UV that only runs while the lights are on (not at night so any nocturnal beneficial life wont get zapped) a ball of cheato and the LR and LS and this has been successful for me, what do you use for filtration?????