How long will aged saltwater last?

[Tex]

Tank is a 100 gal with ro/di water, LR, some corals and about 6" of fish and T-5 lighting.

I've been really really busy and haven't practiced good husbandry in the last month. My bad. I have about 35 gallons of saltwater mixed in a Rubbermaid trashcan in the garage. It has been sitting there for over a month with a powerhead running constantly. The water looks clean and has no foul smell and all levels test zero. Can I still use this water for a water change or should I toss it and mix some new water?

 

[seaham358]

I have used SW that has been mixed over a month.. As long as you have a PH in there it should be fine. Some say that some minerals will precipitate out, so you may want to test cal and alk and see... If its low then you may want to dose the tank after the wc.

 

[melosu58]

I think you will be OK if you had a power head in it.

 

[tecwzrd]

With only 6” of fish in a 100 gal I’m surprised you have to do much more then monthly pwc.

Even if you didn’t have a ph going 24/7 properly aged SW won’t “spoil” IME and is fine as long as you re-aerate it for a couple of hours prior to use and make sure your ph/sg/ca is still in target range of the main.

 

[Tex]

Thanks for the replies. Not that big a deal, I could always pour it out and start over but with a 200 gal salt mix costing $70 and ro/di water I figure the water is worth $85. No sense in pouring $85 down the drain. I'll test and use based upon the results. BTW - the trash can has had a tight fitting lid on it with a tiny vent hole. I kept it covered to keep contaminents like auto exhaust fumes and dust out.