Salt (blue bucket) mixing time

[Randy Holmes-Farley Verified Community Expert]

Understood but it's still a curious oddity that mixing for longer then that 20 minutes with out a significant increase of temp could cause precipitation like shown in that video. Plus the Coral Pro version's parameters aren't that drastic. Around 470 Calcium and 1400 Mg could be expected (see sig). The elevated Mg should help balance the higher Calcium.

Continuous mixing of a salt should not cause precipitation(beyond anything initially as the salt is added) if the temp stays with in reason (like the video states 24-26C or lower.) I don't see it happening or why it would happen.

Edit: and yes I understand preciptation on say a pump shaft could happen. But not a full tank snow storm.




Any salt mix is susceptible to a precipitation event especially if temperature is increased.


http://www.reefkeeping.com/issues/2005-07/rhf/

I suspect the water got unusually warm in their video so they could have a dramatic effect.

 

[Randy Holmes-Farley Verified Community Expert]

I always left my IO stirring overnight, then let it sit unstirred as I used it over a month or so.

 

[jason2459]

I suspect the water got unusually warm in their video so they could have a dramatic effect.

Yep, that's all I got out of the video. That little pump is generating quite a bit of heat compared to the small volume of water. They didn't show or say what the temp of the water was.

 

[CJBuckeyes]

I always left my IO stirring overnight, then let it sit unstirred as I used it over a month or so.

I've heard rumors that the residue from mixing IO salts is an anti-caking agent / clay used to keep calcium and carbonate from reacting. If true, does this help against precipitation after it's mixed, or only in the solid state?

 

[Rob Lion]

I suspect the water got unusually warm in their video so they could have a dramatic effect.

Then I am confused, why a major salt/equipment and testing company would show something that makes their product look bad on video, if it wasn't legitimately trying to warn its customers of what not to do.

 

[Randy Holmes-Farley Verified Community Expert]

I've heard rumors that the residue from mixing IO salts is an anti-caking agent / clay used to keep calcium and carbonate from reacting. If true, does this help against precipitation after it's mixed, or only in the solid state?

I do not believe that is accurate. A friend liked to lower his alk (and also pH) using muriatic acid, and got zero precipitation from normal IO. I never did that, and there was tons of calcium carbonate in my IO mixing barrel.

I don't consider precipitation a problem. There is more than enough alk in most salt mixes, and the calcium drop is small.

 

[Randy Holmes-Farley Verified Community Expert]

Then I am confused, why a major salt/equipment and testing company would show something that makes their product look bad on video, if it wasn't legitimately trying to warn its customers of what not to do.

Well, don't do what they did.

Anyway, they are probably just trying to show that precipitation can be reduced by keeping the time and temp down, which is true. pH too.

The reason it precipitates is that alk is so high.

 

[Randy Holmes-Farley Verified Community Expert]

Yep, that's all I got out of the video. That little pump is generating quite a bit of heat compared to the small volume of water. They didn't show or say what the temp of the water was.

FWIW, a rise from 25 to 40 deg C drives the supersaturation of aragonite in seawater from 3.0 to 4.8, so the effect is fairly large. Some is the reduced solubility of calcium carbnate at higher temps, but an even bigger effecdt is the shift in pKa of bicarboante, making more carbonate at a given pH and temp.

I show calculations here:

Chemistry and the Aquarium: Calcium ? Advanced Aquarist | Aquarist Magazine and Blog
http://www.advancedaquarist.com/2002/3/chemistry

from it:

Comparing the increase in supersaturation due to solubility and acidity changes between 25 and 40 °C for aragonite, we find a change from W = 3.0 to 3.3 due to solubility, and from 3.0 to 4.4 due to the bicarbonate pKa shift. Together these effects yield a supersaturation of 4.8 for aragonite.

and


What do these values really mean? The following combinations of calcium and alkalinity have the same supersaturation in seawater:

1. Normal seawater at 80 °C
2. Seawater at 25 °C with calcium raised to 1300 ppm
3. Seawater at 25 °C with the alkalinity raised to 8.2 meq/L

It makes sense that all three of the situations above could lead to precipitation of calcium carbonate, and that is exactly what happens on the surfaces of hot objects in our tanks.

 

[Rob Lion]

I always left my IO stirring overnight, then let it sit unstirred as I used it over a month or so.

I never did that, and there was tons of calcium carbonate in my IO mixing barrel.

so over TIME, even without a heat source, you got precipitation too

 

[jason2459]

so over TIME, even without a heat source, you got precipitation too

lol

I would guess most of that was due to the initial dumping of salt and mixing and nothing like shown in the video after the water cleared.

 

[Sir Chris]

I start mix then clean tank up and maintainence tank and by that time bout an hour I change 10-20% based of water test. I current have HOB a DIY skimmer that I use at night that goes in the tank and deep sand bed. And a fat belly mandarin that's 9 months old in tank.

 

[jason2459]

Well, I have some Red Sea Coral Pro on it's way. Lets see what happens.

 

[TylerS]

Interestingly enough I emailed red sea directly with a similar question last night. I forgot to specify blue bucket vs coral pro though. My plan is to mix up a whole bucket, then let it sit while I use it over a month or two. They said after it mixes up to pull out the heater and pump and let it sit at room temperature (which I specified was in a 60F basement). They mentioned that I might get some precipitation so I should just measure the "elements" before adding to the tank and dose if necessary. Unfortunately they didn't clarify what elements... thinking about it now I'm going to follow up on that.

 

[benapilot]

Doesn't really answer anything other then that little pump is generating quite a bit of heat in that very small volume of water. He didn't say what the temp of that water was just if the water is significantly higher then 24C it could cause precipitation. I agree a large pump that generates a lot of heat or a heater in the water will cause some precipitation. I also agree mixing beyond what's needed isn't necessary unless the saltmix contains organics of some kind.

But circulating the water continuously with out significant temp increase should not cause precipitation. If it did everyone's tanks would be a white cloud all the time.

I have a 20 gallon aquarium I use as a new salt water holding tank. I mixed about 15 gallons worth of Coral Pro at room temp and turned the power head on. I forgot about it and left the pump on all day. When I finally remembered it, the water was super cloudy... Two days and I'm still waiting for it to clear up!

Weird stuff!

 

[skipb1956]

I'm new to the hobby and read a few books that seemed to recommend keeping enough water ready in case you needed to refill your tank so I have a 33 gall brute which I keep full. After reading this I'm thinking thats not a good idea? I do have a heater and powerhead in there. Am i losing some of the good stuff out of the water?

 

[saltyfilmfolks]

I'm new to the hobby and read a few books that seemed to recommend keeping enough water ready in case you needed to refill your tank so I have a 33 gall brute which I keep full. After reading this I'm thinking thats not a good idea? I do have a heater and powerhead in there. Am i losing some of the good stuff out of the water?

Re read Randy's post. Your fine.
I will say after only seven or so years I've never had a problem mixing any salt ever.
Il take that as yet another small blessing in my personal reef life and I'm grateful.

 

[jason2459]

I have a 20 gallon aquarium I use as a new salt water holding tank. I mixed about 15 gallons worth of Coral Pro at room temp and turned the power head on. I forgot about it and left the pump on all day. When I finally remembered it, the water was super cloudy... Two days and I'm still waiting for it to clear up!

Weird stuff!

Thanks for the input. I want to see at what temp the water turns cloudy like whats in the video.

I'm new to the hobby and read a few books that seemed to recommend keeping enough water ready in case you needed to refill your tank so I have a 33 gall brute which I keep full. After reading this I'm thinking thats not a good idea? I do have a heater and powerhead in there. Am i losing some of the good stuff out of the water?

Take out the heater and no need to keep stiring unless the saltmix you use has some kind or oganics in it. You're good to go. If you need to do a large water change then add the heater in just before use.

 

[chefjpaul]

I let salts sit, unstirred for long periods of time as well, the red sea salts (both) can leave a pretty musty smell. I just re mix for a few minutes.

I've never experienced any ILL effects from.

But, red sea salts mix up so fast it's usually not necessary to leave sitting around.

 

[USMC4Life]

I use instant ocean and never had a problem.

 

[Randy Holmes-Farley Verified Community Expert]

Interestingly enough I emailed red sea directly with a similar question last night. I forgot to specify blue bucket vs coral pro though. My plan is to mix up a whole bucket, then let it sit while I use it over a month or two. They said after it mixes up to pull out the heater and pump and let it sit at room temperature (which I specified was in a 60F basement). They mentioned that I might get some precipitation so I should just measure the "elements" before adding to the tank and dose if necessary. Unfortunately they didn't clarify what elements... thinking about it now I'm going to follow up on that.

They mean calcium and alkalinity. That is what precipitates, and any changes to magnesium are likely within the testing uncertainty of the kit.