Usually the way you want to deal with this is to incrementally increase it by little bit – for instance if you are sanitizing on a weekly basis. It also depends on what kind of ongoing controls you have, whether you have got a UV light in the system or filters in addition to whatever chemicals sanitization you are doing. If you do have any of these ongoing controls, then you can extend it to much longer periods of time safely because you are preventing the re-inoculation from occurring with the UV or filter. Once you find out how long is too long in the frequency you just allow the biofilm to develop in the water system and you might have created the hardest challenge of getting rid of it again. So be careful about lengthening the time between the sanitization. If you have got something that works and it’s not too onerous, stick with it.