Affect of salinity on alk/calc test kit results

[Reef_Hobbyist]

Why is it that my alk/calc test kit results change with salinity? If I let some evaporation take place without replacing it to bump up my salinity, my alk/calc readings are higher. If I add some RODI to decrease my salinity, calc/alk readings are lower.

Are the test kits designed for a specific salinity? I happen to be using Salifert.

And if it matters, this is in a large volume system of 900 gallons so it takes a lot of evaporation or addition of RODI to affect my salinity.

 

[Sabellafella]

Why is it that my alk/calc test kit results change with salinity? If I let some evaporation take place without replacing it to bump up my salinity, my alk/calc readings are higher. If I add some RODI to decrease my salinity, calc/alk readings are lower.

Are the test kits designed for a specific salinity? I happen to be using Salifert.

And if it matters, this is in a large volume system of 900 gallons so it takes a lot of evaporation or addition of RODI to affect my salinity.

Unforunantly no the test are based on ur current alk and calc. Think about it like this, only the h20 evaporates out of the tank leaving everything behind, so your minor and major trace elements will go up with your salinity. The best way to raise salinity is to add fresh saltwater to ur autotop off. Itll will keep levels stable depending on ur desired range salt mix

 

[Reef_Hobbyist]

Unforunantly no the test are based on ur current alk and calc. Think about it like this, only the h20 evaporates out of the tank leaving everything behind, so your minor and major trace elements will go up with your salinity. The best way to raise salinity is to add fresh saltwater to ur autotop off. Itll will keep levels stable depending on ur desired range salt mix

I don't know why I didn't think of that. Seems so obvious now!! Thx