Salt Equation

cdawson

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Jan 6, 2003
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Someone posted this salt equation a while back

"Basically anything you place in the tank will displace water. Estimate how many gallons you have and multiply by 0.286 in order to get the amount of salt you need. This is figure produces a specific gravity of 1.014 in my water."

What's the equation to produce 1.012
 
I was the one that posted this equation. I found that this amount of salt will produce a specific gravity of 1.014 when I mixed it with water. I have found this out through trial and error. I do not know exactly how much salt will produce a specific gravity of 1.012 since I did not record how much salt I used to produce each individual figure. Obviously it would be less, I would suggest that you use less salt in increments and test each time until you reach your desired level.
 
Keep in mind that temperature affects the hydrometer's ability accurately determine specific gravity, so what works in one location might not work in another.

I'd get a hydrometer and test, just to be sure, rather than relying on an equation.
 
I've got one, I just wanted to know roughly how many cups I needed to add to the new 135 to get my current salinity. I'm on a tight budget right now and I've only got half a bag of salt left I don't really want to waste any salt. I can't get more for another week and a half ( I bought the tank and stand with most of my pay cheque, and started paying for a new truck!).
 
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Understood. Start by adding the salt slowly, letting it mix, test, add, mix, test. It's always easier to add more a bit later. We use this method anyway--we mix about 60 gallons of water at a time, so add salt to get close, then add a bit at a time, til we hit the mark.
 
this is the formula that I use. It uses ppt instead of specific grav. and the quantity of salt is given in grams.

(increase of ppt desired) 3.8 (gallons) = salt

I.E. if i wanted to raised the salinity of a 10 gallon tank by 5ppt the problem would look like this:

(5ppt)3.8(10gallon) = 190 g salt needed

hope this helps
 
Something else to keep in mind...The amount of salt in your salt mix is not a constant. Some brands vary more than others, and none vary significantly, but things like humidity will alter the salt.

Double checking is a must, no matter what method you use to get close.
 
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