Salinity Calculation

[e34stx]

Hi everyone,
i hoping someone can help me calculate how much water to remove from my tank to maintain the correct salinity. so i do the randy sodium hydroxide, Calcium and tropic marin part c method. my tank is a redsea peninsula 500 so i reckon after rock work etc i have around 450l of water. i dose 215ml of both kh and ca and 430ml of part c. could someone show me how to work out how much water to remove to keep the salinity at 35ppt. i use a milwakee refractometer which has a resolution of 1 ppt, i also have the hanna conductivity salinity pen but i dont really trust the readings as they seem to fluctuate a fair bit dispite calibration.
thanks for any help

 

[vetteguy53081]

I usually remove 3 Chinese quart containers of water and check after adding RODI water until I’m back in safe range

 

[Randy Holmes-Farley Verified Community Expert]

Hi everyone,
i hoping someone can help me calculate how much water to remove from my tank to maintain the correct salinity. so i do the randy sodium hydroxide, Calcium and tropic marin part c method. my tank is a redsea peninsula 500 so i reckon after rock work etc i have around 450l of water. i dose 215ml of both kh and ca and 430ml of part c. could someone show me how to work out how much water to remove to keep the salinity at 35ppt. i use a milwakee refractometer which has a resolution of 1 ppt, i also have the hanna conductivity salinity pen but i dont really trust the readings as they seem to fluctuate a fair bit dispite calibration.
thanks for any help

I think you will find it quite challenging to exactly calculate how much to remove each day. While it can be done, I don’t think it worth the effort.

I’ve gone through a more general case for my diy two part that I’ll post in a minute.

 

[Randy Holmes-Farley Verified Community Expert]

This is about the amount of rise expected;

http://reefkeeping.com/issues/2006-02/rhf/index.php#19

Residue Remaining from Recipe #1 when using Recipe #1, Part 3A

After one year of adding 8 ppm of calcium and the accompanying 0.4 meq/L (1.1 dKH) of alkalinity per day (41 mL of both parts per day or 4 gallons of both parts per year in a 50-gallon aquarium, including the effect of the magnesium part #3A, 2440 mL/year), the following residue (Table 2) would remain after calcification and adjustment for salinity (there is roughly a 32% rise in salinity over a year using this addition rate without water changes).