Lowering Salinity?

[NewShrimp]

Hi everyone!

The other day, I measured my salinity for the 1st time out of curiosity. I was surprised to see it was at 25 ppt or 1.018 sg. I know that they can survive this salinity, especially since they have for the past 2 years, but it seems to be way above their ideal range. Since I've had them, they always remain in their lava rocks, and only wander a little bit at night, so I began to wonder if they were unhappy with the salinity. I topped off the tank with some distilled water and it dropped to 23 ppt or about 1.017 sg. Since then, they have been venturing out from their rocks a lot more and picking at things away from their rock hideout. They seem happier with the change, but I'm wondering if I should lower it more so it's in their ideal range since my research says 10-15 ppt (although they can tolerate more or less) to keep them the happiest. Should I lower the salinity more, and if so, do I have to do so slowly, or can I just take out some of the tank water and immediately add distilled water?

Thanks for the help!

[kuanyu1993]

Even though they are tough, it's always safer to do it slowly.

There are online calculator for sea water, which tells SG at given temperature and salinity.

[Mustafa]

Yes, you can lower it that way if you want. Have they been breeding the last two years? If yes, then there's no need to change anything.