Salt mixing : How do you get the same salinity every time?
- Thread starter ColinAbi
- Start date
DrawnToBeaches
New member
I'm not as strict about my salinity it is +/-.003 usually but I do measure my salt to water when I mix and test before I change the water, but like I said always within .003
DrawnToBeaches
New member
I do both, it's always measured just never perfect
bundybear1981
New member
For me I measure using an old cup to get a ball park figure then adjust / fine tune with more salt until I hit my mark. I usually let it sit mixing about 10 mins between salt additions.
bundybear1981
New member
I think your maths is out there, 1/2 cup per gallon is 12 cups for 24 gallons You've done 1/4 cup.
ColinAbi
Hola
I did 6 full cups instead of 12 half cups.
ColinAbi
Hola
Refractometer
bundybear1981
New member
You needed 24 half cups (at 1/2 cup per gallon) or 12 full cups.
Space heater
New member
Yea, you only added 1/2 as much as you should have.
0.5 cups/gallon * 24 gallons = 12 cups
I've done the same thing when making odd amounts of water, but it's easily corrected.
bundybear1981
New member
I run 2 methods (depending on the container), both have a pre-determined water volume.
One I count out how many cups I need (this is for the smaller container)
For the larger volume one I have 2 marks, one for RODI water level and one for post salt level.
I have a powerhead for mixing, both I confirm with my refractometer to ensure I have them at 35.
One I count out how many cups I need (this is for the smaller container)
For the larger volume one I have 2 marks, one for RODI water level and one for post salt level.
I have a powerhead for mixing, both I confirm with my refractometer to ensure I have them at 35.
ColinAbi
Hola
Does the salt make that much of a difference in the water level?
Happyschneider
New member
Here is what I do.
1) prepare the approximate amount of water I need
2) let water heat to the temp I need (salt dissolves much easier)
3) add about 90% of the salt I expect (weighing exactly how much I added) = salt[added], let dissolve for about 10 minutes
4) measuring salinity using a refractometer (calibrate regularly) =sal[current]
5) calculate how much salt I need to add
X=salt[added] * (sal[wanted]-sal[current]) / sal[current]
Where sal[wanted] is the final salinity. I would recommend to work in salinity (ppt) rather than density (the 1.026 most use) as density is dependent on water temperature. You would need to make sure that your new water has more or less the same temp as the DT water.
This is a fast way for me to get a reliable salinity without knowing the exact amount of water that is in the tub.
1) prepare the approximate amount of water I need
2) let water heat to the temp I need (salt dissolves much easier)
3) add about 90% of the salt I expect (weighing exactly how much I added) = salt[added], let dissolve for about 10 minutes
4) measuring salinity using a refractometer (calibrate regularly) =sal[current]
5) calculate how much salt I need to add
X=salt[added] * (sal[wanted]-sal[current]) / sal[current]
Where sal[wanted] is the final salinity. I would recommend to work in salinity (ppt) rather than density (the 1.026 most use) as density is dependent on water temperature. You would need to make sure that your new water has more or less the same temp as the DT water.
This is a fast way for me to get a reliable salinity without knowing the exact amount of water that is in the tub.
Yes. I mix water in a 30g tank, i have a mark at 12g, 10g for my 55g tank and 2g for my 20g sps tank, after i add salt the water level has risen about 3/4ths an inch so it does make a pretty good difference.
Like i said i use a mark for where the ro/di waterline should be then in a container i have marked by cup i add 6 cups of salt and it gives me 12g of water at 1.025. Always double check sg before changing
Space heater
New member
I mix 2-10 gallons at a time, and while I have a good idea of the volume (number of cups) it takes I use a cheapo kitchen scale from Target to measure the salt. I can't remember the numbers off the top of my head, but I have them written on a note card I keep in my refractometer case. Like Happyschneider, I add 95% of what I expect to need, let it dissolve for a couple hours, then add the rest slowly until I hit the salinity I want.
serbusfish
New member
I use D-D H2Ocean+. This salt requires 1KG of salt for every 25 litres of water, so I simply measure out 1KG of salt, dump into 25 litres of water, and mix. Super simple.
