This product is designed to help boost the biological in your tank. It contains nitrigying bacteria that are vital to prevent ammonia toxicity. By populating your tank with nitrifying bacteria, before adding fish, you reduce the chances of an amonia spike; which is the number one reason for fish loss. Bio start should be added at the start of the tank. Bio Start can be used with your water change maintenance and should be used in conjuction with a water conditioner.
Please keep in mind, that you should be testing your water regularly to monitor your water levels.