Concentrated Salt Solution

[Aaron Stone]

Questions: Would it be possible to mix up a concentrated saltwater solution to store and use medium term (say two months) that could be diluted to the standard concentration for water changes?

Problem: I am trying to setup an auto water change system that can change 10% weekly (25 gal) and can go for two weeks in auto mode. I do not have space at or near the aquarium for a 55 gallon drum for sufficient salt water storage. I do, however have RO/DI production nearby which is currently automated with a solenoid for top off.

Solution: I would like to have a concentrated solution of salt water at the aquarium that could be dosed to a separate container and mixed with RO/DI before being used for auto water changes. Ideally something around a 4x to 5x or greater concentrate would be used.

Besides the obvious instrumentation requirements, does anybody see any issues with mixing and using salt in this manner?

 

[A_Blind_Reefer]

@Sisterlimonpot is doing something of the sort to add super salt to beat the evap wall with kalkwasser. He’s a bit more than an average diy guy, and what he came up with sounded pretty involved but amazing. He posted the mathematical formula (I think) to come up with volumes for someone else who recently asked a similar question. I’ll try to find that post and link it but don’t hold your breath as I’m not that good with that. If I don’t post back in a few maybe he’ll reply. Good luck! It sounds like it may be overkill for a temporary application, but I’m not judging….ha

Edit. I think I actually found it

Awc with high salinity storage to reduce footprint

I'm new to reefing and I'm looking to build an auto water change system with a small footprint because it all needs to fit in my living room. I have 150 gallon tank, an RODI unit, apex & the dos and can do the plumbing from the RODI unit installed under the kitchen sink and to the drain there...

www.reef2reef.com

 

[Aaron Stone]

Appreciate it, I will hunt as well.

Overkill is my middle name.

 

[A_Blind_Reefer]

Appreciate it, I will hunt as well.

Overkill is my middle name.

Linked it above

 

[GARRIGA]

Water can hold tens time the level of sea water. 350 ppt. So I’ve read. Could try my axing up 70 ppt then keep increasing salt content until it no longer dissolves. I’ve done this to bring mollies from 12 ppt to 35. Found I could take tank water and add 2x the salt content and it mixed pretty well just shaking. Didn’t dissolve fully but wasn’t needed. Just had to raise overall and salinity.

Can’t see a reason why storing a higher concentrate wouldn’t work. Hadn’t thought about that but makes sense and may try the same. Only one way to find out but not dojng it with salts having some bio additive. Only that which normally has an extended shelf life such as TM Pro.

 

[Aaron Stone]

Agreed, though my concern is more with alkalinity, calcium, and magnesium and how they stabilize.

Thank you for the link

 

[Devisissy]

Wait, sister is a dude?

 

[A_Blind_Reefer]

Wait, sister is a dude?

Well, I shouldn’t assume. I’m not so hip to the rules these days and probably shouldn’t assign gender. Full disclosure, I’ve never personally met or asked about preferred pronouns. I’ve listened to a few of the videos and apologize if I offended anyone….purely an assumption based on audio clips alone. Well and I thought a name came up in conversation once….which again led to an assumption

 

[Sisterlimonpot]

Wait, sister is a dude?

Yep... does that mean all my advice goes out the window for you? Haha

Agreed, though my concern is more with alkalinity, calcium, and magnesium and how they stabilize.

Thank you for the link

That's the main issue with concentrated brine. You have to be careful with major element precipitation.

I mix 2 bags of instant ocean into a 55g drum to get roughly 60ppt. I just dump them in and don't see any precipitation. But the unknown is precipitation of the minor elements. I can't be certain that those get lost.

@A_Blind_Reefer linked my post. It's pretty simple to plug that formula into an excel sheet so that you can input the mixed brine solution and it will spit out the mixture for both.

 

[Devisissy]

Yep... does that mean all my advice goes out the window for you? Haha

Nope. I've decided we are all dudes on this website even us girls.

 

[DCR]

I think calcium is very likely to precipitate as carbonate when you concentrate it that much along with the alkalinity and it will be difficult to get it back into solution. Could be issues with lesser elements as well.

 

[Randy Holmes-Farley Verified Community Expert]

Hyperconcentrated seawater risks precipitating calcium carbonate since both alk and calcium rise a lot.

At the very least I’d verify this isn’t happening at the concentration you want to use.

In general, I do not recommend this.

 

[Aaron Stone]

Thank you all, I appreciate your input.