Salinity and water evaporation

[wigwam]

I have a 40 breeder with salinity at 1.023. What will my salinity be if 1 inch of water evaporates? How about 1.5 inches?

Assume no rock or sand for water displacement. Only thing in the tank is water.

 

[Bunnee911]

Very good question. Mark the outside of the tank and measure with your refractometer. I would like to know the results.

 

[nervousmonkey]

Very good question. Mark the outside of the tank and measure with your refractometer. I would like to know the results.

There are calculators that can tell you that based on total water volume in gallons or liters, but I like Bunnees advice. Mark your tank and measure it yourself so you know for sure. Best way to be confident of the results.

 

[TheEngineer]

1.023 is 30.5ppt. That converts to 30.5mg/liter. A 40b is 151.4 liters (let's round that to 150). An inch of water in a 40b is 10.6 liters.

A full 40b (150liters) has 4575 mg of salt in it at 30.5ppt. If you remove 10.6 liters, your total volume is now 139.4 liters. Do the division and you wind up at 32.8 ppt or 1.025sg.

 

[nervousmonkey]

1.023 is 30.5ppt. That converts to 30.5mg/liter. A 40b is 151.4 liters (let's round that to 150). An inch of water in a 40b is 10.6 liters.

A full 40b (150liters) has 4575 mg of salt in it at 30.5ppt. If you remove 10.6 liters, your total volume is now 139.4 liters. Do the division and you wind up at 32.8 ppt or 1.025sg.

D***. We all just got schooled by @icecool2

Wigwam, now you have your answer

 

[TheEngineer]

D***. We all just got schooled by @icecool2

Wigwam, now you have your answer

Ha! Only if I'm right and didn't mess up a conversion.

 

[melev]

Who doesn't top off their tank to avoid this happening at all?

 

[Cory]

Need to know how many gallons 1 inch is. Plus tank dimentions.

 

[TheEngineer]

Who doesn't top off their tank to avoid this happening at all?

For science!!

 

[Randy Holmes-Farley Verified Community Expert]

Here's a little easier way to calculate than icecool did, but the answer will be the same (within the approximations made):

The height of a 40 breeder is about 16 inches.

So if there is 16 inches of water and you take out 1 inch (to 15 inches deep), the salinity rises by 6.7% (which means you multiply the salinity by 1.067, which is 16/15).

That would take the specific gravity from 1.0230 to 1.0245.

(1.067 times 23 = 24.5. )

 

[TheEngineer]

Here's a little easier way to calculate than icecool did, but the answer will be the same (within the approximations made):

The height of a 40 breeder is about 16 inches.

So if there is 16 inches of water and you take out 1 inch, the salinity rises by 6.7% (which is 16/15).

That would take the specific gravity from 1.0230 to 1.0245.

(The 24.5 is 1.067 times the 23. )

Well, yeah if you want to do it the easy way I was trying to show it in a more generalized fashion so it could be extrapolated to other tanks

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, I edited my explanation and math slightly after your post, but it is essentially the same.