How Long Can I Keep Salt Water Stored?

I was just wondering how long I can keep freshly made salt water stored in a tank with a circulating pump in it? I want to make a large volume for water changes to keep on hand. Maybe a 40 gallon plastic trash can. Does it go bad?

 

just as with our tanks, the SG will slowly lower, but on a much lesser scale, I would think, with the 40g storage, as you have more volume and just water. I would just check it weekly. keep it somewhat cool to keep down on evap. also circulate with powerhead/pump to keep SG constant.

 

I do the same thing in a 55g Rubbermaid trashcan. Just top off with fresh water to compensate for evaporation loss & you should be good. 50g usually last about 2 weeks unless I get lazy.
If you plan on keeping it longer, then I would definitely cover it or keep in a closed container.

 

FWIW, I've been storing SW in my DT for a couple years now...


I do keep a bucket of extra SW too. I keep a lid on it (one of those air tight lids/bucket combos from Home Depot).

If I need to use it, I'll pull it out and put a PH in it and a heater for a day, then use it.

 

I'm fairly sure the SG will rise. That's only if the lid isn't airtight.