How long will Forget About It For Boats live in the tank?
There are many variables that contribute to how long the patented blend of probiotic bacteria will live in a holding tank. Size and location of the tank, temperature and usage all will have an impact. Like any living and growing organism, food and water are the primary concerns. As long as there is water and food, it will continue to grow and multiply by consuming the food source. Under normal usage with full tanks that is going to take some months to consume 100% but it will consume everything eventually. If it consumes all the food before the tank goes dry it will not harm anything. If it goes dry before all the food is consumed, it will not do any harm. In either case, just add more per the instructions for the size of the tank and start over again the next boating season. Hopefully you can enjoy your boat often enough that you can flush it to feed it every time you visit your boat.
Recap: Flush it to feed it every time you visit your boat.