How to dilute salt water (reduce salinity)

RacerX308e · 01/06/2007, 12:19 PM

I have a batch of salt I mixed at home and brought to my office in five gallon buckets. In checking with my refractometer, the SG is 1.030 in the new mix and 1.025 in my tank.

I need to dilute the new before I do the water change and need to know how to calculate how much RO/DI I will need to reduce five gallons of 1.030 to 1.025.

I would much rather dilute by combining a bit of RO/DI as I put the new mix in as opposed to take home, empty jugs in to the holding tanks, recalibrate and then refill and cart back down.

Another thought though, I mix at home at 78 degrees and the jugs are now at room temp or about 70 degrees. How much difference does that make?

Thx

roons · 01/06/2007, 01:11 PM

your an attorney?

RacerX308e · 01/06/2007, 01:33 PM

Yes. Why? Do you not help attorneys?

jasper24 · 01/06/2007, 01:44 PM

What percent of water are you changing? If it is 15% or less I would just add some ro/di water to the mix 1/2 gallon or so. The difference in SG when doing a water change of small proportion will not make a significant difference. I would stick a heater in the water for a few minutes to get it within a degree or two. I do 10% water changes weekly and aim for a + or - 2 degree temp difference. My display SG is 1.025 so I shoot for between 1.023 and 1.026 on my change water. No problems.

RacerX308e · 01/06/2007, 01:57 PM

15 gals in a 55g with sump. So probably 25% change. Need to do change soon b/c ORP is dropping a bit.

Misled · 01/06/2007, 02:21 PM

Quote:

Originally posted by roons
your an attorney?

LMAO

mhurley · 01/06/2007, 02:26 PM

Quote:

Originally posted by roons
your an attorney?

And this has any bearing on the topic because of what?

Racer,

I've seen some calculators online for figuring this out, but it's not straightforward. My suggestion is too swap out 1 gallon of salt water for 1 gallon of RO/DI, check the salinity...repeat.

The temp difference should be compensated by your refractometer as long as it is an ATC type (Automatic Temp Compensation). Even so, 8 degress is not going to make a huge difference. In the same right, 15 gallons of +.005 sg in a 55 gallon system is not going to move the entire system very much at all. I would almost say to not sweat it at all and do the change.

RacerX308e · 01/06/2007, 02:49 PM

Thx for all the help. I made the change, swapped 2 gals of non-salt and SG in the tank is the same as it was before 1.025.

I just get more and more nervous as I have stocked my tank over the past year and it is starting to finally look like something. Would die if the tank crashed.

01/06/2007, 12:19 PM	#1
RacerX308e Registered Member Join Date: Jan 2004 Location: Indianapolis, IN Posts: 130	How to dilute salt water (reduce salinity) I have a batch of salt I mixed at home and brought to my office in five gallon buckets. In checking with my refractometer, the SG is 1.030 in the new mix and 1.025 in my tank. I need to dilute the new before I do the water change and need to know how to calculate how much RO/DI I will need to reduce five gallons of 1.030 to 1.025. I would much rather dilute by combining a bit of RO/DI as I put the new mix in as opposed to take home, empty jugs in to the holding tanks, recalibrate and then refill and cart back down. Another thought though, I mix at home at 78 degrees and the jugs are now at room temp or about 70 degrees. How much difference does that make? Thx

01/06/2007, 01:11 PM	#2
roons Moved On Join Date: May 2005 Location: saugerties ,ny Posts: 1,240	your an attorney?

01/06/2007, 01:33 PM	#3
RacerX308e Registered Member Join Date: Jan 2004 Location: Indianapolis, IN Posts: 130	Yes. Why? Do you not help attorneys?

01/06/2007, 01:44 PM	#4
jasper24 Registered Member Join Date: Jan 2005 Location: Marietta, GA Posts: 2,120	What percent of water are you changing? If it is 15% or less I would just add some ro/di water to the mix 1/2 gallon or so. The difference in SG when doing a water change of small proportion will not make a significant difference. I would stick a heater in the water for a few minutes to get it within a degree or two. I do 10% water changes weekly and aim for a + or - 2 degree temp difference. My display SG is 1.025 so I shoot for between 1.023 and 1.026 on my change water. No problems.

01/06/2007, 01:57 PM	#5
RacerX308e Registered Member Join Date: Jan 2004 Location: Indianapolis, IN Posts: 130	15 gals in a 55g with sump. So probably 25% change. Need to do change soon b/c ORP is dropping a bit.

01/06/2007, 02:49 PM	#8
RacerX308e Registered Member Join Date: Jan 2004 Location: Indianapolis, IN Posts: 130	Thx for all the help. I made the change, swapped 2 gals of non-salt and SG in the tank is the same as it was before 1.025. I just get more and more nervous as I have stocked my tank over the past year and it is starting to finally look like something. Would die if the tank crashed.