First of all let me say thanks to all the member input and info on this site, it has been invaluable in getting started. Now the question, I have a small barrel system starting using ammonia to cycle, it has a river gravel bed using a bell siphon to cycle. My plan is once the system is started and operational, to use it as a donor of gravel and water to start tote system when I have the first one in place. Has anyone ever did this? It sounds logical too me but how much mass in gravel/water will I need to start the tote? My barrel setup is probably about 30 gallons of water and about the same in river gravel.