did I burn my rock?

[chilihedkc]

I just got my live rock yesterday. I placed it in my newly set up display that had been running for about 4 days at what I thought was about SG1.024, or 1.025. I had used a refractometer scaled in brix and made the conversion. About 6 brix equals SG 1.024 or so. My new hydrometer also showed up yesterday and for giggles I gave it a test run. WOWZA! Off the freakin chart on salinity. I'm talkin 1.040+.
So I immediately drain most of my sump and replaced it with fresh, treated water (not ro/di, I didn't have the time) to dilute the toxic soup. Took me about an hour to get it down to an acceptable level. So, did I just kill all my new live rock? It looked beautiful by the way. Is there anything else I could have done differently other than using ro/di?

[thegrun]

While you probably did kill off some of the life on your rocks, chances are some will survive. Are you sure your new refractometer is correct? I'd check it against one at your LFS to be sure. Of more concern is what exactly is "treated water"? You may have issues for some time if you introduced phosphates or nitrates in this "treated water".

[der_wille_zur_macht]

The absolute amount of phosphates introduced from one emergency water change are not going to cause long-lasting effects in a reef tank - if there was that much phosphate in your drinking water, you'd have more serious problems. It's certainly not an ideal approach, but not the end of the world.

Likely, you killed some life, but the rock is certainly not a loss. Just keep an eye on it for dead or decaying matter - try to siphon it off or blow it off with a powerhead if you see it. Keep in mind that on the reef that rock came from, it could have been exposed to air or tumbling around half buried in sand before it was harvested. And then, it sat for days (at least) with hardly any water on it at all while it was shipped here. So no big loss for it to be in a hypersalinity solution for a little while.

Just be glad this happened now, and not when your tank was fully populated.

And I'll second the recommendation of checking your instruments against something known.

[Sugar Magnolia]

I'm confused. You checked your SG with a refractometer and got 1.024. Was the refractometer calibrated? I'd be more inclined to believe the results of the refractometer than the hydrometer. You said the hydrometer was new. Did you rinse it really well, then rinse it again in tank water before using it? Did you tap it to get the swing arm to settle? I know hydrometers can be off, but that seems really extreme.

[chilihedkc]

The refractometer read dead nuts 0 with ro/do water. Yes, rinsed the hydrometer in fresh water, and soaked it in aquarium water for about a half an hour. It too read 0 with ro/di water, so now I don't know which to believe. There is no LFS anywhere near me. The "treated" water was tap water with chlorine/ chloramine remover. I think it was stress coat. It's all I had, and I was freaking out.

[Salamander]

You don't calibrate a refractometer with RO/DI.

Some use distilled but that's not even too good.

Get some pinpoint 35ppt calibration solution.