How long can I store newly made salt water?

[All-in Salt Tank]

Hello! I've read some of the posts about this but I'm still not clear on this topic. I have a 4-stage RODI system and make approx. 50 gallons of salt water every week with Instant Ocean salt. I've been trying to get the nitrates down in my recently purchased/moved tank and I've been doing 50% changes on my 100G tank weekly. My nitrates have gone down a lot (off the charts to the 40-50 range) and I'm trying to back off to every other week water changes.

I don't always measure how much I remove from the tank exactly with how much water I make, so I sometimes end up with a little extra. Last week I stored some of the extra salt water in a 4 gallon water jug with a cap (pic below). It was warmed to 80 at the time of the change, but has been sitting at room temp for over a week. I'm hoping to use this water for top-offs between water changes.

Questions:

-How long can I store this salt water without circulating or aerating?

- How long can you store fresh RODI water in these jugs?

Thanks for your help!

 

[exnisstech]

Do not use saltwater for top off as it will raise your salinity. Water evaporates but salt doesn't. RODI only for top offs.
I use instant ocean and store water for weeks. I keep a 32g brute full at all times.
Not sure about rodi storage in those clear jugs. I use a brute container to store RODI also.

 

[Reef By Steele]

Don’t know about RODI, but they sell salt water sealed like that. As far as I know, it can be stored for as long as you want.

I mix salt water for our cultures and store in these bottles for up to two weeks. I use it by then so could store longer. With it sealed there isn’t any evaporation so salinity should remain stable.

 

[Sophie"s mom]

Do not use saltwater for top off as it will raise your salinity. Water evaporates but salt doesn't. RODI only for top offs.
I use instant ocean and store water for weeks. I keep a 32g brute full at all times.
Not sure about rodi storage in those clear jugs. I use a brute container to store RODI also.

Good to know because I have wondered the same, except I do put a power head in mine to keep it circulating. I usually only mix it a few days in advance, but knowing I can store it for weeks is great. Thank you

 

[Reef By Steele]

Duh!! Culligan sells RODI in the water bottles so I would assume it can be stored long term in them as well.

Issue with storing in something like a brute is over time it will evaporate and you will need to top off to keep salinity stable. Plus unless you keep a lid on it, pollutants can get into it.

 

[LPS Bum]

If the container is sealed you should be able to store saltwater for a long time. Weeks for sure. Maybe months. Just make sure the salinity is right when you go to use it (evaporation).

Water changes are a great way to initially bring down nitrates (as you’ve done) but not always the best way to keep them in check long term. Changing that much water that often gets expensive, and is very labor intensive. Maybe consider upping your filtration when you get the levels to where you want them, so that you don’t have to change so much water all the time? Just a thought…

 

[exnisstech]

Issue with storing in something like a brute is over time it will evaporate and you will need to top off to keep salinity stable. Plus unless you keep a lid on it, pollutants can get into it.

Well the lid also prevents evaporation. Just saying I'll get some condensation inside on the lid but nothing more. I've never had salinity increase storing in a brute with lid for a few weeks.

 

[twentyleagues]

I store mine in a brute w/lid for about 2 weeks at a time. Thats enough water for 2 water changes on my 2 tanks once a week. Salinity is fine, as @exnisstech said I get condensation on the lid I just bang the lid once or twice before I open it. Heat and flow the entire time. I have stored smaller amounts in a sealed water bottle in the past no issues there either. Forgot about one for maybe 6 months, it tested fine.

 

[threebuoys]

Generally, you can store RO/DI or mixed salt water indefinitely. Only downside would be if contaminates get into either and you have an algae bloom of some sort. As others , I use a 32 gallon Brute trash can. I keep it full of mixed saltwater so it will be available whenever I need it.

 

[Paul B]

-How long can I store this salt water without circulating or aerating?

50,000 years give or take as long as you add some water from evaporation. I have been storing it for many months. No problems yet.

 

[All-in Salt Tank]

Do not use saltwater for top off as it will raise your salinity. Water evaporates but salt doesn't. RODI only for top offs.
I use instant ocean and store water for weeks. I keep a 32g brute full at all times.
Not sure about rodi storage in those clear jugs. I use a brute container to store RODI also.

Thanks! Do you keep your salt water circulating in the Brute cans? That's what I have to mix, too, but one time it got slimey on the sides before I even added salt. I may have has the top off though. It's been fine in the closed jugs though.

 

[All-in Salt Tank]

Duh!! Culligan sells RODI in the water bottles so I would assume it can be stored long term in them as well.

Issue with storing in something like a brute is over time it will evaporate and you will need to top off to keep salinity stable. Plus unless you keep a lid on it, pollutants can get into it.

I've never bought RODI, only made my own. Assuming new jugs might have an expiration date? Assuming long-term means a few weeks or months?

 

[All-in Salt Tank]

Generally, you can store RO/DI or mixed salt water indefinitely. Only downside would be if contaminates get into either and you have an algae bloom of some sort. As others , I use a 32 gallon Brute trash can. I keep it full of mixed saltwater so it will be available whenever I need it.

Do you keep the salt water circulating or just store with lid on?

 

[Reef By Steele]

I've never bought RODI, only made my own. Assuming new jugs might have an expiration date? Assuming long-term means a few weeks or months?

I said, duh, to myself. I can’t exactly remember the emergency, may have just been a new tank, but I bought water from our Culligan store once. That’s why I know they bottle it as well as just filtered drinking water.

In my 43 gallon brutes I run quiet one pumps. 500 goh ok, but I prefer the 1000 gph as it mixes the salt faster. I never used the lids, as I try to use it faster than that out of the brutes.

I have found instant ocean to create a brownish build up in the tote. Never saw that with my Fritz RPM blue box but this last batch is so don’t know if they changed something.

I wipe down the containers regularly and disinfect.

 

[threebuoys]

Do you keep the salt water circulating or just store with lid on?

Usually keep it circulating with a small, cheap pump, I'm not sure that's necessary, but it is helpful when I add salt to the RO/DI. Once I plug it in, I just let it keep running. I do keep a lid on it. I have the Brute sitting on a covered porch so have to keep it clean.

Edit: I also notice the brown sediment, and I get a little bit of calcium(?) build up on the bottom. But I never wipe it out or disinfect the Brute.

 

[Randy Holmes-Farley]

A salt mix without organics added to it can be stored closed and unstirred and unheated.

Heating high alk salt mixes (even just with a stirrer) is undesirable as it encourages calcium carbonate precipitation.

Mixes with organics in them, such as Reef Crystals, have the potential for bacterial growth, and in those cases, I’d keep it stirred to prevent it from possibly becoming anaerobic.

 

[JayM]

A salt mix without organics added to it can be stored closed and unstirred and unheated.

Heating high alk salt mixes (even just with a stirrer) is undesirable as it encourages calcium carbonate precipitation.

Mixes with organics in them, such as Reef Crystals, have the potential for bacterial growth, and in those cases, I’d keep it stirred to prevent it from possibly becoming anaerobic.

Not that I'm disagreeing, but what's considered "high alk", and why would heated and circulated encourage precipitation in storage, but not in a display tank?

 

[Randy Holmes-Farley]

Not that I'm disagreeing, but what's considered "high alk", and why would heated and circulated encourage precipitation in storage, but not in a display tank?

Raw salt water is far more prone to precipitation because in an operating reef tank, phosphate, organics, and even whole bacteria bind to bare calcium carbonate surfaces and prevent them from acting as seed crystals for additional precipitation.

That effect is clearly seen for high alk mixes such as Red Sea Coral pro where they warn against mixing too long fir that reason, and have a video showing it precipitating.

There’s no magic number. The higher the alk and pH, the more likely is precipitation (unless pH is below 7.7 or soon which case no precipitation will take place).

Heat reduces the solubility of calcium carbonate, which is why it deposits on pump impellers and heaters.

 

[Kzang]

A salt mix without organics added to it can be stored closed and unstirred and unheated.

Heating high alk salt mixes (even just with a stirrer) is undesirable as it encourages calcium carbonate precipitation.

Mixes with organics in them, such as Reef Crystals, have the potential for bacterial growth, and in those cases, I’d keep it stirred to prevent it from possibly becoming anaerobic.

I’ve never stored saltwater, but I’d read that overtime the alkalinity decreases. Do you know if this is true or not?

 

[Charles Zinn]

One thing not mentioned is algae production. keep any rodi or salt water in 6 gal containers. If tanks not kept out of light you will get algae production which grows over time. I've been told rodi is stable for long time and saltwater has a shelf life of 2 months or less.