salinity

[Jon Schuch]

Anyone good at salinity math? I mixed up 5 gallons of Red Sea. The 2 1/2 cups I put in made it 1.035 so how many gallons of ro di water will I need to bring that down to 1.024?

 

[Redfoxtang]

3 cups! Just kidding!! I would just add a little RODI water at a time until your down to your set salinity.Testing after adding water of course! 5 gallons isn’t much so shouldn’t be a lot of RODI water!

 

[ichthyogeek]

1.035(5) + 1.000(x) = 1.024y
where x = the number of gallons RODI you use, and y = the toal number of gallons you have.
x+5=y

5.175+x=1.024y = 1.024(x) + 1.024(5)=1.024x+5.12
5.175+x=5.12+1.024x
.055 = .024x
x = 2.291666... gallons

Tada!

Also I did most of this in my head, so if your calculator says differently and you're taking PEMDAS into account, go with that instead

 

[highest_tides]

3 cups! Just kidding!! I would just add a little RODI water at a time until your down to your set salinity.Testing after adding water of course! 5 gallons isn’t much so shouldn’t be a lot of RODI water!

+1

Add cups at a time..mix for 15 minutes and recheck. Then repeat if necessary.

 

[highest_tides]

Also, when I get a ton of salt at once I mixed it dry and place in a different bin so my 1/2 cup per gallon is consistent. Hope that helps

 

[Kryptonian]

You're going to get so used to mixing 5 gallon buckets. Just adjust each time you mix a new 5 gallon and you'll get it down quick. Next time try 2 cups and see where you come in, then adjust.
Maybe just pour 1/3rd of it into another bucket then add RODI to get yourself down to 1.024. The exact math will become more tedious than learning the right ratio that works just by guess and test. You already have a starting point (has to be less than what you tried the first time).
Even if you do the math, you're probably still going to test salinity before adding to your tank anyway. I do.

 

[Lizbeli]

Honestly, I tried to make mine an exact science once but it still is slightly different each time I make a batch. So now I add a bit less than I think is needed. Keep testing and adding as I go. I have spare rodi nearby if I go too high. Always test before using the water.

 

[splitting_lanes]

I mix 26.9 oz of Red Sea coral pro salt with 5 gal of water to get 1.025