The Salinity Is Too Darn High!

[cgfetch]

Hi all,

We started our saltwater FOWLR back in February, and have been relying on the accuracy of hydrometers. Oops.

We just purchased a refractometer, and have discovered the SG is 1.031.

We have a 55g tank. How can we safely lower the salinity?

Thanks.


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[icydeath]

Take some water from your reverse osmosis tap, and prepare 20-22.5 gallons of water at a interval equal to that you are missing it by. So if you wanted the water at 1.025 and you are at 1.031 and you have like 40 gallons of water ACTUALLY in the tank, then the interval is 0.006. Prepare half of the actual gallons in the tank at 1.019 then slowly replace the water by taking out a gallon or two of water from the tank, and introduce a gallon or two of the other water every hour or two.

Best of luck! - Raymond

 

[icydeath]

Remember to temp match and pH match etc!

 

[bribo12]

via Imgflip Meme Maker

Lol

Sorry I didn't contribute but icy hit the nail on the head.

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[cgfetch]

So it would be unwise to remove some water and slowly add fresh water? And what salinity would you guys recommend? It seems 1.025 is "normal". I don't have any plans for corals in the near future.


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[icydeath]

You could do that but it is a lot more inaccurate because the math goes as such.

x=amount of 1.031 water left in tank after water change
y=amount of water changed/freshwater put into the tank
z=amount of actual water in tank (40 gallons for math)

1.025z = 1.031x + 1.000y

The equation then becomes this (assuming you replace 25% of the water):

1.025(40) = 1.031(30) + 1(10)
41 = 30.93 + 10
41 = 40.93

So you are going to want to do ABOUT a 25% water change. Not sure what will happen to your pH

But if it is 8.5 and your tap water 7 the equation you would want to do regardless of the values is:

if x = pH of tank
y = pH of tap
z = end result

(x*0.75+y*0.25) = z

(8.5*0.75+7*0.25) = z
(6.375+1.75) = z
8.125 = z

So remember to do it slow if you do the fresh water way and use my equation to pH check.

 

[icydeath]

The salinity depends on the livestock but I think 1.025 is the normal specific gravity.

 

[cgfetch]

I appreciate you taking the time to write all of that out. While I love numbers and math, I'm leaning toward your first recommendation, as it seems to be less likely to destabilize the ecosystem. I'll report back in a few days and let you know how I made out.

Thanks again!


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[icydeath]

Alright! Any time I like math too. Took a little thought to perfect it though.

Good luck!