What's my salinity? It's driving me crazy.

[chome360]

I can't pin this down, and if I can't even pin down my salinity, I know I don't stand a chance here.

So I've been running with Tropic Marin Pro since I started the hobby about a year ago. I used a refractometer and came in at 1.025. Everything was fine, fish were happy, no coral. about 6 months ago I got a Hanna digital reader and switched to that. I didn't know they could be off so easily, so I trusted it fully. I did notice that to get to 1.025 for water changes, I wouldn't have to go quite to 1/2 a cup per gallon. I'd got with about 18 scoops (using 1/2 cp) to 20 gallons of RODI.

About a month ago I decided to test the water from the LFS when I got some snails. Happened to use the refractometer and it read 1.040. That was my first time thinking something is off. I did a bunch of testing, but have only managed to confuse everything.

As of right now, here's what I see:

From the DT
Hanna reads 30.7
Refractometer reads 37
2nd refractometer also ready 37

I've already calibrated the Hanna using their calibration fluid, and it reads 35 using that
The refractometers read 1 when using rodi water, although I know that's not the right way
When I use exactly 1/2 Tropic Marin to 1 gallon of RODI, my refractometers do read 1.025, Hanna reads low, closer to 30. But then the LFS coming in at 1.040 again this weekend when I bought another snail...

I did add some GSP, an leather and a BTA right before all this went downhill. They looked great for a couple weeks, now seem to stay mostly closed. Clownfish and Skunk Clearner Shimp seem happy.

At this point I have no good ideas on what my salinity actually is, or how to know for sure.

 

[dvgyfresh]

I’ve only ever used refractometers , test tap water should be at 0 then test tank

 

[BryanM]

I have a milwakee and gave up on it being accurate. Back to a standard refractometer now, and if it reads rodi 0 I feel its good.

I may get a tropic marin hydrometer and just do away with all the rest though.

 

[GSPClown94]

Use Randy's DIY calibration standards http://reefkeeping.com/issues/2004-06/rhf/index.htm

 

[chome360]

I have a milwakee and gave up on it being accurate. Back to a standard refractometer now, and if it reads rodi 0 I feel its good.

I may get a tropic marin hydrometer and just do away with all the rest though.

I'll checkout that hydromter, thanks.

I just ran to the store and picked up some distilled water to calibrate the refractometers instead of using RODI. Calibrated down to zero. After that, the current reading on the tank is 1.024 --- 33

 

[chome360]

Use Randy's DIY calibration standards http://reefkeeping.com/issues/2004-06/rhf/index.htm

I'll check it out, thanks

 

[dvgyfresh]

I'll checkout that hydromter, thanks.

I just ran to the store and picked up some distilled water to calibrate the refractometers instead of using RODI. Calibrated down to zero. After that, the current reading on the tank is 1.024 --- 33

Last sanity test would be get Saltwate from fish store , figure out the salinity and then test it at home