Salinity issue - Advice please

[tripper]

I use a hydrometer to check my salinity for my water changes. I was placing an order from Marine Depot the other day and decided I would order a second one just as a "check." I got the Instant Ocean hydrometer and went to check my salinity last night . . .

My original hydrometer read 1.023, right where I want it. This new one read 1.031!!!!! Needless to say I was a little shocked. Now I don't know what to do. I have always felt like I had to add more salt than the directions said, but I figured I was just miscalculating.

All my fish are nice an healthy. So I have 2 questions:

1) What are the effects of high salinity on fish?

2) Should I bring my salinity down to the appropriate level based on the readings of the new hydrometer?

Looks like it might be time to invest in a refractometer!!

TIA

tripper

[fishfreek]

Did you confirm that there where no air bubbles on the swing arm of the new hydromoter? I always flicked the case of the hydromoter a few times to bump off any bubbles if they existed. Even the smallest bubble can affect the performance of the hydromoter. In addition old hydomotors often provide false readings but that kind of difference is unusual.

A)

1) The higher the salinity the more the fish's metabolisum will have to work to expell the salt from their system.

2) I would run a half dozen tests a few minutes a part to confirm the validity of both results. Like I said air bubbles can affect performance in addition to several other variables. If your still having this very large difference in results I would suggest putting your salinity at a middle point between the two.

[macman7010]

hydrometers are very ineffective at telling salinity. the best thing to use for accurate salinity readings are refractometers.

[malkore]

...and I totally agree, get a refractometer. You can be paranoid and re-calibrate it with RO/DI water every time you test the tank, and ensure you're getting accurate readings every time.

[fishfreek]

I wouldnt make such blanket statements. I have both and used a hydromoter for years before I got a refractomoter. What I found after calabration was that my hydromoter was only off by something like .002. So my hydomoter might read 1.025 and my refractomoter would read 1.023 or 1.027. I cant remember which way it was off.

[tripper]

fishfreek,

I tested both multiple times last night and was very careful to get air bubbles off. I have a feeling my old hydrometer is bad. I will probably end up buying a refractometer, but for the immediate future I may buy ANOTHER hydrometer to validate.

Am I right in assuming that there are no real long-term effects of the high salinity as long as I get it under control soon? Would the fish display any abnormal behavior to indicate that the salinity is too high?

tripper

[mastershake]

take the water to an lfs, have them test it, see what they get, i have the instant ocean one and its .001 too high, my old bosses was the same as that, he calibrated them all to a big glass hydrometer before using them, chances are your old one is a lil whacked, check it with the lfs, see what they get

[revhtree]

I had 2 of the IO hydros and 1 coral life. They were all different!!

I got a refractometer, and calibrated it. After checking the salinity with it, I found out that one of the IO hydros was right on with the refractometer. SO....I use the hydro for a quick check all the time..

I agree with mastershake.....take your water to the lfs and see...

[tripper]

Thanks for all your advice! I will take a sample to the LFS.

tripper

[IndyReefMan]

I doubt that you have caused any long term ill effects to your livestock, they've acclimated to it by now. What will hurt them is if you try to lower the specific gravity too quickly (assuming you discover that the specific gravity is really that high). If you do lower it down, do it very sloooowly.