Ah. More than 1 Saltwater reef tank. I have tried running a 180 and a 55 Gallon tank at the same time - quite frankly I don't have the right equipment, finances or desire to run 2 tanks. I am in the processing of Shutting down my 55 Gallon Tank again (yes I done this before). It was the maint. required for 2 Tanks that actually got me. I also have a 20 Gallon Freshwater tank (it is my daughters, but I end up taking care of it too). So my plan is to Shutdown the 55 Gallon Tank, Clean it and Set it backup as a Fresh water tank. Move my daughters Freshwater livestock into it and Shutdown/Get rid of the 20 Gallon Tank. That should all be done over the next 2 Months.