Did I just recycle my tank?

[blecki]

I have a Hannah salinity reader that was recently recalibrated using the provided solution and I also have a hardly used Red Sea refractometer. Hardly meaning I’ve only used 5-7 times so it should not have wandered too far off of when I got it. Hannah was giving me a 1.021 and Red Sea gave me a 1.026. I average the readings, giving me 1.023. Both should be accurate so I’m having difficulty figuring out which is correct.

Every hannah salinity tester I've ever used has been off, even after calibration. Conductivity just is not a very reliable way to measure salinity. I use them for things like matching salinity during acclimation but not as a reading. Your refractometer loses it's calibration even when not in use, but for the purpose of salinity in the reef you can calibrate it against RODI water - RODI should read exactly at the bottom of the chart, and the error introduced at 35ppt by calibrating this way isn't an issue.

Get a reliable hydrometer. Seriously. That's a heck of a swing.

In theory a hyrdrometer is the best way but they need to be broken in and since you can't calibrate them the marking on the chart will never match the actual reading so you need another instrument to figure out how far off the arm is. At least they are consistently off unlike the other two.

7.6 when my kit was saying 8.0.

Measuring PH at the LFS doesn't always work. Specifically if it's hotter in your car/outside/the LFS than in your tank you would see PH drop.

But, ammonia seems weird to me. Measured it at .4 - .8 this morning using the Red Sea marine care kit when it was .2 - .4 yesterday. Used the API this morning and it read .50.

Are you measuring free ammonia or total ammonia? I think both of those measure total. Kinda ironic here, if your PH reading is accurate and your ammonia reading is accurate, then raising your PH could be a serious issue. At 7.6 PH most (all?) of that ammonia will be bound up in the form of ammonium which is much less toxic. I wouldn't try and raise PH until the ammonia reads 0. Also if you dosed prime or something similar your ammonia readings are garbage. Prime causes false positives on the api tests and probably others.

I going to assume nitrite or nitrate spike.

Neither would kill the fish.