Mixing salt via slurry

[reefrunner69]

I just got a new box of salt and need to do a water change tomorrow or the next day. I was intrigued a month or two ago when I read how a poster on another forum mixes his salt. Basically making a super saline slurry, and then adding that to RO/DI water to make your water change water. This seems to me, would solve the problem of getting inconsistant results throughout a bucket or bag of salt, by mixing the entire box/bag at one time, but also solve the problem of how to store 25-50-200g of SW in between water changes. I only change 5g every couple of weeks, so a 50g box lasts me quite a long time. I did have a couple of questions though.

1) How long is the slurry good for after mixing?

2) Do you need to keep it mixing until it is all used up, or can you simply mix for a few hours prior to making another batch of water?

3) Is there a minimum amount of water that needs to be used to per amount of salt? For instance, I bought a 25g box of salt, can I mix this with 4-5 gallons of RO/DI water, or do I have to have a minimum of 10 or whatever?

4) How long do I need to mix the slurry before using it to make SW for a water change?

5) After adding the slurry to some RO/DI water for a water change, how long do I need to let that mix before using it?

 

[yaksplat]

There is a point of satuaration of a solution. At this point, you will not be able to dissolve any more salt into the water at the current temperature. You'd be best off mixing the salt with room temperature water to prevent precipitation of the salt from a super saturated solution due to the temperature dropping.

You'd probably be best off figuring this out by experimenting/trial and error.

Start out with a 5 gallon bucket with a powerhead in it. Add 4 gallons of water at room temperature. Start adding salt, keeping track of how much you add to the solution. Keep adding salt until it no longer dissolves. You may be able to start out with much less water.

The Final amount of salt can be used for future reference.

Once you have your saturated solution, check the salinity of it. From there, you should be able to ratio the final mixture as following , using parts per thousand.

Some please correct me if i screwed this up my brain is already numb here at work.

desired ppt= solution ppt(volume of solution needed/ total volume)

so if you wanted 100 ppt of salt in a gallon of water, and your solution contains 520 ppt of salt, you would use 24.6 oz of solution and 103.4 oz of RO water. In this case our total volume is 128 oz.

The mixing should be just about instantaneous. If you really want to get tricky now, you could determine the exact temperature that your RO water should be to have a final temperature of 80ºF.

necessary RO water temperature = (final temperature - (solution temperature)*(solution volume/total volume))/(RO volume/total volume)

in our case here it would be 83.6ºF RO water to have a final water temperature of 80ºF

Hope this helps somewhat

Jim

 

[GrndHog]

Slurry??

 

[yaksplat]

i would advise against using a slurry. You cannot easily determine how much salt is in a given volume. Think of salt mush. Lot of salt, a little water, that's a slurry.

Jim

 

[GrndHog]

LOL, Slurry it is

 

[scuba_steve]

rr if ya only doing 5 gallons why not just mix the 5 gallons when ya need it and using an airline to drip it in !!?? would take mabe 10 min to dose it like that ?!?! before i had 5 tanks i would do my water changes this way !! but instead of dripping id mix a 2 gallon bucket wait for it to clear and then drop into the tank !! and would wait 15-20 and add more till the tank was full !!

 

[reefrunner69]

The reason is because dry salt, just like a sand bed will have the larger particlas/grains rise to the top. Settling will cause an uneven distribution of the salt mix before you ever use it. Then if I just scoop 5g worth off the top, I'm not getting the results I should from the salt. Even if the manufacturer could guarantee a uniform particle size, the difference in densities of the elements would still be an issue. I'm just looking for a better way of making an evenly distributed salt. I don't have the facilities to mix the entire 25g, much less a 50g mix and store what I don't use until it's gone, I can, however, store a 5g super saline solution and use small amounts of that to mix with RO/DI water every couple of weeks till it's gone. I read about this method and found it interesting.

 

[jamal-188]

It does sound very interesting. I think I'm going to try doing this. I have a couple 30g garbage bins I use. Think I'll start with 10g and see how much salt will dissolve with a powerhead in there then figure out what SG it is and how much fresh water I'll need to add to each gallong of super salt water.