Whether you’re filling your aquarium or fish tank up for the first time or you’re bringing an old one out of storage to return your fish to it you should know what the proper procedure is in order to avoid damaging the tank, or worse your fish. To properly set up your tank then fill the tank with tap water and set up the pump, filter and water heater. Now set the water heater temperature to 20-22c (never set it higher than this as you will risk boiling your fish… but some species of fish will require different temperatures to others so makes sure you check first before settling on a temperature). Now you’ll need to leave the tank as it is for a few weeks in order to prepare the water for your new fish. While you are doing this you should ensure that the light is on for around 6 hours a day and not more than 8 and that you pump is on permanently 24/7. Now after six weeks you will be ready to have your water tested. Take a sample of your water in a bag or in a Tupperware box to your local fish shop.