I don't use my RODI often. I have water set aside in gamma sealed 5 gallon buckets. My concern is what is the safest way to store the unit with out risk of slimy bacterial invaders or other nasties building up inside it. Should I keep it filled? Drain it? Maybe this is a non-issue, but I can't swing replacing it. While on the subject, how long is my sealed water good for? Is there a half-life on RODI water? Thanks in advance. Lauren