1. You should take out any carbon filters in the aquarium when you are medicating your fish. The carbon in the filter will remove the medicine from the water, so it is best to remove it all together.
2. It is not advisable to leave your aquarium lights on at all times for the aquarium. You should keep the lights on for 8-12 hour periods at a time. If you want to keep the tank lights on when you arrive home, simply get a timer for the lights so your fish stay on a schedule.
3. You need to have some healthy natural bacteria to process the wastes and chemicals in your aquarium. This will take around 4 weeks to grow naturally, but you can purchase products to speed up the process.