How Long Does Mixed Water Last

[Plandauesq]

I have a 200 gallon mixing tank outdoors. If If I mix 200 gallons and do a 100 gallon water change, how long is the remaining 100 gallons of mixed saltwater good for? Any issue using it 2 weeks later?

 

[TCoach]

BRSTV did an investigates on this. Most salts were good for 4+ weeks. My only concern would be if being outdoors caused bacteria/algae growth in your tank.

 

[Plandauesq]

BRSTV did an investigates on this. Most salts were good for 4+ weeks. My only concern would be if being outdoors caused bacteria/algae growth in your tank.

Thanks. My concern as well. How would you figure out if this is a problem?