Lowering high salinity with TM Part C (Balling)

[Randy Holmes-Farley]

If your salinity rose. All of the other elements should have risen as well. Right?

No. The rise is assumed to have come from a two part adding Na+ and Cl-, not from evaporation.

Potassium is unchanged from that, but then would get lowered in a salinity correction.

 

[MnFish1]

No. The rise is assumed to have come from a two part adding Na+ and Cl-, not from evaporation.

Potassium is unchanged from that, but then would get lowered in a salinity correction.

Thanks. However if it was from evaporation or from mixing a batch of salt incorrectly I would assume just adding RO would be correct?

 

[Randy Holmes-Farley]

Thanks. However if it was from evaporation or from mixing a batch of salt incorrectly I would assume just adding RO would be correct?

Yes.

 

[Vested]

OK, I think we are good to go now.

I'm showing Hans-Werner's calculation above, and working from it.

The 3 g/l excess sodium chloride he uses comes from the salinity being 38 ppt, when you want 35 ppt. (that assumes you got to 38 ppt by starting at 35 ppt and using an unbalanced two part to add sodium chloride).

If you have a different high salinity value, such as 37 ppt, you alter that 3 g/L number (say, to 2 g/L for 37 ppt starting value).

The amount of Balling Part C you want to add is 30/70 x this value, or 30/70 x 3 g = 1.3 g/L. If the value of excess sodium chloride is smaller (say the 2 g/L mentioned above, then it is 30/70 x 2 = 0.85 g/L Balling Part C.

The L values in the 1.3 g/L or 0.85 g/L represents the total liters in your aquarium, not the amount you are going to change.

Thus, for 250 gallons = 946 liters, you would be adding (in total) 1.3 g/L x 946 L = 1230 grams of Balling Part C.

That amount fixes the ionic composition in the 250 gallons, but not the salinity.

If all that was added at once (dry), then the salinity would rise a bit above 38 ppt (38 g/L + ~1 g/L) = 39 ppt (I'm estimating the amount of water already in Balling Part C, it will be off a bit)

Then use the calculator to figure out how much RO/DI would need to swap out from ~39 ppt to get to 35 ppt, and put all the Balling part C into that volume and change away.

Beautiful, this is the conclusion I got to as well for some reason I was really stuck on wanting to calculate the salinity the ro would be at with the part c added but sounds like it is not necessary or part of the equation.

My only concern still would be with how to slowly add that water, if I'm doing multiple water changes I will be re-pulling from whatever salinity 10 gallons brought it down to for example. I don't think it will be that big of an effect though and the calculations aren't worth the effort to figure out like 2% difference if that makes sense lol.

 

[Randy Holmes-Farley]

Beautiful, this is the conclusion I got to as well for some reason I was really stuck on wanting to calculate the salinity the ro would be at with the part c added but sounds like it is not necessary or part of the equation.

My only concern still would be with how to slowly add that water, if I'm doing multiple water changes I will be re-pulling from whatever salinity 10 gallons brought it down to for example. I don't think it will be that big of an effect though and the calculations aren't worth the effort to figure out like 2% difference if that makes sense lol.

Since there's no rush to do it, I'd personally aim to lower salinity by no more than half a ppt per day, and going slower or skipping a day here and there is fine.