Saltwater expiration date?

[frankthetank]

How long can saltwater stay good bottled up?
I ask because I made up some saltwater in a couple 5 gallon jugs because I was suppose to have my sump/fuge ready this weekend. Well, I ran into a slight delay and don't have it ready. But the saltwater has been sitting in the jugs for about 3 days now.
Typically I mix up the saltwater and let it sit overnight (about 12 hours) before adding it to the tank. So this is a little longer than normal.

 

[earlybird]

If you have a PH running in the buckets I think 3 days is okay. You could go longer I'd imaging but I would test first to double check. pH, alk, cal, mg.

 

[frankthetank]

No these are just water jugs. I generally make up saltwater, shake the **** out of it for several minutes and then again and again periodically throughout the evening, and then let it sit over night and add it to my tank the next morning.
However, with my delay of building my sump... it's been sitting for 4 days now. I'm hesitant to add it to my tank... how would I know? I can test everything you mentioned but Mg. Don't have that test.

 

[earlybird]

I wouldn't add it but that's just me. I have no idea of it's worth at this point? Also, consider mixing your water in an open 5g bucket or a garbage can with a good powerhead. It's best to let your salt mix for at least 24hrs. Not to get the salt dissolved, that happens fairly quickly, but to oxygenate the water. RO water has a very low pH and the buffers in the salt need to meet with the air to increase the pH.

 

[dude23455]

I keep saltwater mixed for weeks in a 30gal barrel in my garage. I do keep a power head running in there.
Saltwater sealed in jugs will be fine for quite a while. Just give it a good shake before you add it to the tank to oxygenate it.