Stored Saltwater - shelf life?

[holy carp]

I have a food-grade 5 gallon bucket that I've been using to store my saltwater. The buckets were originally used for kosher vanilla yogurt that I picked up free of charge at a local caterer. I washed them out with scalding hot tap water and no detergent. I'm using the Reef Crystals with RO/DI (TDS meter reads 0) water, and I've been using this particular bucket for months.

 

My latest batch at 1.025 has been sitting in the bucket for about 2 weeks. The bucket has a sealing snap-on lid, and in the kitchen it has probably been around 80 degrees. I've often had some tan colored sediment at the bottom of the bucket (which as I understand isn't that unusual for Reef Crystals or Red Sea). But this time, there were odd streaks that were on the side of the bucket. They were all vertical with an apparent point of origination from which they spread up and down.

 

Has anyone seen anything like this? Is it chemical or biological? Is it safe to use?

 

[Hig789]

Not sure about the stuff in the water but you might want dump it and use some vinegar in the water you wash it with. Not sure water alone would remove everything.

 

I believe I read Randy Farely Holmes say that after the salt is mixed in that it could be stored indefinitely without stirring. I think some salt mixes say to use it within a certain amount of time though.

 

What brand of salt is it? Mine sits for about a week before I use it. I mix it right after I do a water change so I have it on hand if I need it. I always slow it to mix again for a few hours before using it though.

 

After you washed the bucket out did you fill it with your RO water and test the TDS?

[Admonition]

Not sure about the stuff in the water but you might want dump it and use some vinegar in the water you wash it with. Not sure water alone would remove everything.

Agreed, wash it out with more than just water.

 

I believe I read Randy Farely Holmes say that after the salt is mixed in that it could be stored indefinitely without stirring. I think some salt mixes say to use it within a certain amount of time though.

Yup. I actually read that thread of his recently and he stated that if the salt was free of organics (ie, strictly synthetic salt) that it could be stored indefinitely without heating or circulation.

 

After you washed the bucket out did you fill it with your RO water and test the TDS?

Another good suggestion. I do this with my new Home Depot buckets after purchase and cleaning.

 

How big is this bucket? Why not use a fresh bucket that hasn't been used?

[ajmckay]

Need more than a picture to tell if the streaks are chemical or biological.

 

I've stored and used SW for weeks/months and haven't had any issues other than it smelling kinda musty - which is probably an indication of some biological activity but hasn't been harmful to use. I typically mix bigger batches so it takes several weeks to use. I usually heat it up and mix/aerate it a little before I use it and that seems to freshen it up significantly.

 

Then again someone will probably come after me and say that you should never no matter what use SW more than 3 days old or something... All I can say is I haven't had any issues using mixed SW after a few weeks. My bucket is black so I can't really say what your black streaks are - but my guess is either some biological film (in which case it should wipe off with your finger) or oxidation of some minerals in the SW, neither of which I would think harmful under most circumstances...

[braaap]

I've left water mixed for weeks before with no issues. I just tend to make it up and use it within a few hours though typically.

[CrazyEyes]

I'd imagine it's good for quite some time, granted you keep it sealed and maybe have some sort of movement ie a small powerhead or an air bubbler.

[GoingPostal]

Weird, I often leave water sitting around in buckets for a few days to a week and usually get a grimy tan crud on the bottom but that's it.

[Hig789]

I forgot to ask. What's the temp like where it was stored at? High temp garage?

 

I store mine in a closet in the house after mixing.

[holy carp]

Thanks for all the replies.

 

I haven't dumped the water yet, so I took a few more photos of the streaks.

 

 

The left side is a closeup of a streak that was above the water after partially draining the bucket.

 

Further details:

The water is stored in the kitchen where there is no A/C in a little manhattan apartment, so these summer days it's typically in the vicinity of 80°F. I don't expect this batch has gone more than 2 degrees up or down, since we've had pretty consistently warm weather the past few weeks.

It has been stored sealed with an airtight lid, though the plastic isn't 100% opaque.

I have 3 buckets, but would be lying if I said they were each dedicated. I typically keep one empty, one full of saltwater (Instant Ocean Reef Crystals) and the 3rd just RO/DI

I have TDS tested the RO/DI in these buckets and they repeatedly come out at 0ppm (my tap water in nyc registers 53ppm)

 

The water in the photos has almost no odor. It actually smells much less than a freshly mixed batch.

 

And the bottom has some spots as well - they aren't streaks as the bottom is obviously horizontal.

 

The streaks feel sort of dusty to the touch, not slimy. Almost a tiny bit granular, so I'm assuming it's some type of precipitation. Looking closely, there seem to be a few spots in the center of the origin of the streaks.

 

In my sci-fi imagination, there's a magnetic field in the building causing the iron in the precipitate to align in a vertical manner. Like I said - imagination and I claim no basis in fact.

[GTi]

I think RC has organics in it and they either precipitate out or allow some bacterial growth. I have had the streaks too whenninput the water on and don't get around to using it for a few days.

[holy carp]

I decided to use the water for a PWC, and it seemed to show no unusual effects (the elegance coral closed for a few hours, as it often does when the water is changed).

 

I've made a new batch with 0ppm RODI and I/O Reef Crystals to exactly 1.025. Mixed it for 1.5 hours at 75-77˚F and sealed the lid. At the time there seemed to be no noticeable sediment, but I'll check again in a couple weeks to see if the streaking reoccurs.

[rengb6]

I store both RODI and salt water in two 45 gallon containers for automatic top off and automatic water changes (using the Neptune DOS). The salt water is usually depleted over a month. In the year that I've been doing this I've never had any issues. I haven't seen any streaking in these containers but I have experienced something similar when I used 5 gallon buckets to store water for my 16 gallon. I used the water anyway and never cleaned the bucket. Similar to your experience, there were no bad effects.