Thank you so much just replaced my air pump and been struggling with my cloner for three days now trying rubber tape and all kindsa stuff to stop the leaking this was a huge help never would have thought it was the air pump! Thanks a tonWhen taking cuttings/clones and in the 1 inch neoprene pucks, only the pump should be working and plugged into the "always on" . No air stones or air pressure at all or the cloner will leak. When the clones are in the hydro 12, the air stones should be working and the pump plugged into the "timed water". I always just turn my air on and off with the valve thats in the top. Dont know if this helps but..... Good luck!