Why you should never use a Hydrometer

[tbraun]

I have had my tank running now for 7-8 months and I have kept the salinity between 1.026 and 1.028. All this time I have been using a hydrometer to measure salinity. Recently, I acquired a Reflectometer. After calibration, I decided to test my water and it said 1.031. I didn't believe this could be true, so I recalibrated the Reflectometer making sure temperatures were in check. Low and behold... same results. After this discovery, I gracefully put my Hydrometer on my basement floor and jumped on it a few times, making sure it will never see a drop of water again.

How fast can I lower the salinity in my tank?

Can I drop it inside of a day by doing small water changes with RO/DI water or should I span the drop across a few days?

Tim

 

[jason1979g]

I think you should do it over the coruse of a few WC's. about a month or so if you doin weekly wc. just mix the salt at 1.026 and it will come down slowly enought.

 

[Phyl]

It will take a long time using 1.026 water to drop the salinity to 1.026 (you'd have to change 100% of your water to get it there). I'd suggest 1.021, no more than 10%, weekly (or more often if you're ambitious). Make sure you're using RO/DI (not salt water) to top off.

 

[tbraun]

Thanks for the suggestions. I currently use RO/DI water for top off, occasionally mixing with Kalk depending on the Ca level of my tank.

I think I'm going to go with 1.021 for my WC for a while until it comes back down to 1.026.

Do you think it would be safe to take out a gallon of tank water and replace it with a gallon of RO/DI water, once a day until it's back down to proper levels as well? I think this would provide a more gradual drop.

I also noticed I typoed the name... I meant Refractometer, not Reflectometer.. oops.

 

[Hawkeye]

either way will work - as long as you approach it gradually. It's likely the fish adjusted to the higher sg over these past few months. It would be hard on them if you switched it back to 1.026 over a 48 hr period (or something).

 

[panmanmatt]

Dropping the salinity by .005 over a few hours is nothing compared to throwing a fish in a fw bath. When we drip acclimate we are changing the salinity in a short time and for those of us that don't even bother to acclimate new arrivals the change in salinity is even greater.

Temperatures and salinities change with every single tide in nature. .005 is a small change in the grand scheme of things. Personally I'd take out a gallon of water at a time and replace it with RO until you reach the desired salinity. But that's just me and I'm probably in the minority here.

 

[Nickjr000]

Either way i think youll be fine. For future reference those hydrometers are never the best choice for testing. But they're usually closer than yours was. Sometimes you have to rinse them good in hot water to get the salt depoits off , and they'll work better

 

[JRWOHLER]

It is easier on fish to drop the salinaty then raise it. You will find that even if you use RO water and 10% water changes daily it will take a couple days. This is what I do when I drop the salinity in my QT. From 1.023 1.009 takes about a week. Just watch the salinity.