How long can mixed salt RO water sit in an air tight bucket for? 6 weeks okay? TIA

[knutcracker]

what if I don't mix it first? can it sit longer then?

[leebca]

Your worst enemy on mixed saltwater is light. Since the water and salt and air aren't sterile, light will allow many organisms to utilize the nutrients in the freshly made saltwater. The mixed water needs to be in the absolute darkness to discourage any photosynthetic organisms to begin 'feeding' on the nutrients.

However, there are still other organisms that invariably find their way into mixed water stored for a long time, even in the dark and even 'air tight.' These microbes will begin to utilize the nutrients.

You can store RO/DI water before mixing it pretty much for an extended time without too much concern for many of the above mentioned microbes. However, if there is light, some microbes will become visible and reproduce. I would venture to say that RO/DI water can be stored for several weeks. Choose a food-grade container that is colored to prevent light from getting to the water and cover it such that no light can get to it.

This will minimize microbial growth, but you might find it doesn't totally eliminate it.

[knutcracker]

Wow, thanks for the info . . .

i guess that means there is no chance MIXED RO/DI water can stay sealed in a bucket for a month, huh?

[leebca]

Depends on if the bucket lets light through.