R/O water reservoir...

hello out there,

question for u folks that keep a clean water reservoir. do u use anything (besides keeping light out), to make sure no gunk grows inside? h202, Physan20, etc.?

thanks

For plants only, or also for drinking water? I store RO in a 30 gal plastic barrel. It is not air tight and I add nothing to it to keep it fresh. The plastic is not food grade and I would not drink the stored water unless in an emergency.
I go through the barrel every week so the water is not sitting in it for months at a time.
Even with some light exposure I don't think algae can grow in it because it is very low to zero PPM water and there is nothing in it for algae to feed and grow on.