Anyone try Hypersalinity Mix for Continuous Water Changes?

[bar|none]

Hello there. I had an idea and was wondering whether anyone has tried it.

I currently do Continuous Water Changes and love it. I had the idea that I could greatly increase the time till I need to refix my salt mix tank by creating a hyper salinity mix. I am not sure what the limits are until the water will not dissolve anymore salt mix. Then with such a mix, I could dose say half of what I take out.

This will put more load on my ATO, however I plan to set that up to make new RO automatically, so that would be basically unlimited.

Good idea? From a chemistry perspective what kind of PPT would be upper limit?

 

[lynaea75]

Maybe I’m not completely understanding how you mean to implement this but I think that would cause a lot of salinity swings for inhabitants as the water is added then diluted. I expect it would also be less stable to store saltwater that is mixed to a higher concentration.

 

[bar|none]

Maybe I’m not completely understanding how you mean to implement this but I think that would cause a lot of salinity swings for inhabitants as the water is added then diluted. I expect it would also be less stable to store saltwater that is mixed to a higher concentration.

Shouldn't be much different than other concentrated solutions I dose like triton 3 part. If its dosed into the right location in the sump like the pump chamber, it would dilute almost instantly and it's added fairly slowly in my case using a Neptune DOS. Whether concentrated salt mix would be stable is a good question though, and at what concentration.

 

[Randy Holmes-Farley]

Hypersalinity, beyond a small excess, is not going to work out because it results in precipitation of calcium carbonate from excessive alk and calcium levels.

 

[Randy Holmes-Farley]

Shouldn't be much different than other concentrated solutions I dose like triton 3 part.

Except those are stable and hypersalinity seawater is not.

 

[bar|none]

Except those are stable and hypersalinity seawater is not.

oh darn! Thanks so much for weighing in Randy.

 

[Gtinnel]

My awc pumps in less water than it pulls out. I'm using an older industrial pump with no way of calibrating the heads separately. So my solution is to pump water that has a higher salinity back to my tank. So the water I put back into the tank is around 40ppt. If I were you I'd just start mixing salt into some water and see at what point the calcium carbonate precipitates out. You may not be able to make a very, very high salinity mix, but you should be able to raise it some.

 

[bar|none]

My awc pumps in less water than it pulls out. I'm using an older industrial pump with no way of calibrating the heads separately. So my solution is to pump water that has a higher salinity back to my tank. So the water I put back into the tank is around 40ppt. If I were you I'd just start mixing salt into some water and see at what point the calcium carbonate precipitates out. You may not be able to make a very, very high salinity mix, but you should be able to raise it some.

That's a great observation. Calcium is certainly a problem as it doesn't have a lot of buffer before precipitating. A little google and I find an article from Randy explaining this.

Calcium Carbonate Precipitation: Calcium Supersaturation Theory

 

[bar|none]

Ok not giving this up yet. ESV B-Ionic salt is a 4 part mix.

1. Pharmacy grade Sodium Chloride crystals
2. Magnesium Sulfate crystals
3 and 4 The other elements in liquid form

"At 0 °C (273.15 K, 32 °F), brine can only hold about 26% salt. At 20 °C one liter of water can dissolve about 357 grams of salt, a concentration of 26.3%."

Isn't 26% 2600ppt?

Magnesium Sulfate - Solubility in water, 30g/100ml at 20°C

Automate mixing the brine with RO water to dilute to normal strength. Then automate adding the other components. Basically automatically filling a staging tank which would be normal 35ppt reef water when it got low.

Yeah it's too complicated. But could it be done?

Not worth it, but still interesting to think about.

 

[cmoore806]

The problem I see is in confirming the mixed brine/RO prior to putting in the tank. Too much room for error

 

[Randy Holmes-Farley]

Ok not giving this up yet. ESV B-Ionic salt is a 4 part mix.

1. Pharmacy grade Sodium Chloride crystals
2. Magnesium Sulfate crystals
3 and 4 The other elements in liquid form

"At 0 °C (273.15 K, 32 °F), brine can only hold about 26% salt. At 20 °C one liter of water can dissolve about 357 grams of salt, a concentration of 26.3%."

Isn't 26% 2600ppt?

Magnesium Sulfate - Solubility in water, 30g/100ml at 20°C

Automate mixing the brine with RO water to dilute to normal strength. Then automate adding the other components. Basically automatically filling a staging tank which would be normal 35ppt reef water when it got low.

Yeah it's too complicated. But could it be done?

Not worth it, but still interesting to think about.

You are proposing multiple pumps to dose the 4 part salt? I'm not certain how high in salinity each of the parts can get, but that may possibly work.

 

[Brett S]

For what it’s worth, I’ve been doing this for several years now with instant ocean salt. It started as simply a matter of convenience for me. I use a 40G brute trash can for my NSW reservoir and I discovered that one bag of IO salt is a little too much, so instead of measuring the salt out every time I just dump in the whole bag. That mixes to about 45ppt and like you suggested, I then adjust my AWC to take out more water than it puts in which allows the ATO to make up the difference in fresh water.

I haven’t seen any problems or side effects from doing this. I also use my AWC to dose magnesium. I add a few hundred ML of the BRS magnesium supplement to my NSW reservoir each time I add salt and that way my magnesium levels stay pretty stable as the tank gets a small doses of magnesium each time the AWC runs.

 

[bar|none]

Thanks for the thoughtful answers everyone. Putting together a mixing station setup soon. I will make sure it will work in the standard fashion at minimum. Sounds like the simplest may be to not worry about hitting an exact ppt salinity when mixing and prob mix a slightly higher salinity. Then adjust the AWS dosing as per Brett's comment above.