salinity

[DS5000]

New reefer here, currently making my own saltwater for RS 170 45gal with RODI.
Finished making SW, salinity via refractometer 40.
Question - how much RODI do you think is needed to drop salinity to 35ppm - I am just looking for a reference - I dont have a sense yet on how much is needed; is it 1-2 gallons, 10 gallons, etc?

Thanks everyone

 

[NashobaTek]

When mine got high 36ppm it took 3-5 gallons of water to drop it back to 35ppm. I have a 125 .

 

[NashobaTek]

Welcome to the team

 

[Old Fritz]

You'd have to replace about 5 gallons. Easy way to do it is to average the salinity. So if you have a 45 gallon tank at a salinity of 1.030 and you remove five gallons and just add water with a salinity of 1.0 it would average out to 1.026.

 

[Eric1493]

Here's a helpful calculator: https://www.hamzasreef.com/Contents/Calculators/ResultingSalinity.php

 

[DS5000]

can I just add 5 gal of RODI water; or should I replace 5 gal

 

[DS5000]

thx, great calculator!

 

[Eric1493]

can I just add 5 gal of RODI water; or should I replace 5 gal

Replacing will do more, but honestly adding is easier. Just follow the calculator and you'll be good to go. Just a note, don't lower salinity more than 1ppt as to prevent stress. You may want to consider many small additions over time.