Cali Kid Corals

Super concentrated salt solution

cwolfus

cwolfus

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I've often wished I had a larger WC mixing system like others here (ahem, Iani & SeminoleCPA), but I continue to make up my 10g water changes in 5g buckets. That means I use a small portion of a bag of salt each time, which has always been a concern. After all, not only is it not recommend by the salt manufacturers, but logically I would expect settling to make some elements rise to the top of the bag while others work their way to the bottom... not that I have ever had a problem with this in my many years of reefing.

Which brought me to this thought... If mixing an entire bag of salt together is preferred, does it make sense to pour it all into a 5g bucket creating a super concentrated solution? I could then dilute it as needed.

I suspect I may have trouble dissolving all that salt into solution. Do you see other potential issues?

Also, how do our service guy members deal with it? After all you do more water changes than most (I hope) but have to transport your supplies.

TIA

C
 
1 related problems I foresee. 1) as concentration goes up, you will exceed the solubility limits with some species causing them to either not dissolve, or you will reach saturation crystalization. 2) you will likely force irreversible (or near it) precipitation of some elements.
I'm going to blindly guess that you can probably get up to around 10's of % up to double concentration before issues are huge. Not sure if you will gain much for the risk. If you want to test this out get three 5gal buckets and into each add enough salt for a normal 1g mix, a double strength 1 gal mix and a triple strength 1 gal mix . See what you can disolve in 24hr of mixing with say an mj900/koralia 2. If you cant fully disolve the 2x an 3x strength, find out if it is saturation or precipitation by adding an additional 1 and 2 gal of watter (to convert them to "normal" concentrations). If you do this and you still have solids after another 24hrs, you will know it is from precipitation and not saturation.
 
If floor footprints matter, then you can also try to get the tall water containers like

www.tankdepot.com

10 Gallon Capacity
Size: 12"D x 26"H
Part: FEP-10WT

20 Gallon Capacity
Size: 16"D x 29"H
Part: FEP-20WT

45 Gallon Capacity
Size: 18"D x 51"H
Part: TC1851IW
 
Gomer said:
1 related problems I foresee. 1) as concentration goes up, you will exceed the solubility limits with some species causing them to either not dissolve, or you will reach saturation crystalization. 2) you will likely force irreversible (or near it) precipitation of some elements.
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That is what I have been told as well.... but... Fritz had a liquid salt on the market years ago (may still) that is made just for this purpose.
 
I have overshot my salt concentration quite a few times where I would have to dilute 1:2 or 1:3. I do not remember what is the salinity for a 2x or 3x solution but with trial and error it should not be a problem to define. I also keep this 55 gal stock that is stirred constantly with a pump for a month at a time and do not see it precipitate out.
 
2x/3x I have never had an issue but super concentrated you will have problems. That is exactly how they do such things at salt flats.
 
I suspect I may have trouble dissolving all that salt into solution
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I think this is the only problem that really will be an issue, if you use an entire 50g worth bag in a 5g bucket you'll get a concentration somewhere north of 10x the amount. the salt itself takes space as well as the fact I doubt you'll fill the bucket to the brim, so in reality probably look somewhere in the neighborhood of 12x concentration. I'm too lazy to look it up, but if memory serves I think the maximum salt that can exist in water is something like 360 grams per liter of water, at room temperature (more so if you boil it, so 5 gallons of water will hold about 15 pounds of salt, I don't know the exact number but a bag is heavier than that I believe. So you won't even be able to dissolve it all you will get a saturated solution. Also like Tony mentions you'll most like get salt crystals forming as a result of the saturated solution.

Personally I wouldn't worry THAT much about only using a small fraction of the bag, but if really is bugging you simply dump the bag into a dry 5g bucket with a good lid (hell I got plenty if you need those rubberized "moisture-proof" lids) and simply shake the bucket up to mix the stuff around. So when you do use a little portion it hopefully should be mixed nicely.
 
I keep a bucket in the back of my truck on the coast, which BTW has been absolutely plagued by the dripping wet ass fog all summer, not once has my salt solidified.

AFA concentrated salt solution, Lap has a technique he uses, not sure the ratios, but I do know he's been doing it for a while.
 
If your salt mix normally mixes to 400ppm Ca/10dkh alk, tripling the concentration would give you a solution that's 1200 ppm Ca and 30 dkh alk. It's hard for me to imagine that you wouldn't get a ton of precipitation from that.
 
You can look at the Ksp for calcium carbonate and do some calcs to get a rough idea.

But there is a lot more going on that just Ca and alk.

http://en.wikipedia.org/wiki/Calcium_carbonate
http://en.wikipedia.org/wiki/Solubility_equilibrium
 
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