Don't forget when doing water changes, to leave your python above water level. Keeping below water level can cause a build-up of gasses from the pressure of your tap water. Some fish do not handle this well at all, especially Apistos and Discus. I kept having strange issues with my community tank, and come to find out it was because I was doing my WC wrong. Leave the Python above water, so gas exchange can occur as the new water enters the tank.