Running the RO unit directly to my sumps is allowing alot of "creap" which I think is part of my algae problem. So I am going to run the RO to a container and then pump it up to the sump. If I currently use about 1-1/2 gallons of top off per day, how big should the container be? I want to reduce the higher TDS on start up but didnt want to got too big and have the water to sit for too many days and get stagnant.