salinity check

[demifelix]

I had been using a hydrometer all these times and it reads 1.025. I recently started using a refractometer. I calibrated it with the calibrating solution that comes with it carefully. However, my salinity now reads 1.020 using the refractometer. Is this really true that my salinity is really that low and everything is still ok? Does anyone nearby have a refractometer that I can borrow to "calibrate" mine again? Or should I bring water sample to LFS?

 

[hud3339]

If you want to come to Kennesaw you can use mine, it was just calibrated a few days ago by Jenn

 

[cr500_af]

It's possible... I've seen some hydrometers that were dead accurate and some that were way off. IME the "Deep Six" ones have been good, the Instant Ocean ones have not.

That's based on a sample of about five units, so take that with a grain of salt.

I'd be happy to loan you a refractometer, but I have a feeling I'm a touch far from you.
It may be simpler to take yours to a member's house and check it against theirs on their water.

Unless somebody close offers, I'd say LFS... but really, since you just calibrated it with the right solution, I don't see any reason to doubt it.

 

[reefkeeper]

Felix if the hydrometer is one of the glass floating kind, I would trust it before the refrac. I lost several large colonies a few months ago because of my stupitiy and not having my refractometer calibrated. I brought my refrac to Jenn and she immediately discovered what my problem was and it saved me from losing the rest of my corals.

I have one of the original floating hydrometers in my stash now so I can baseline the readings. I also calibrate my unit every couple of weeks now.

 

[peaches7412]

I use a instant ocean refractometer, and it is always off by 0.003(example it reads 1.023, but is actually 1.026). I just bring it to the fish store occasionally and make sure it keeps reading like that.

 

[spankdog]

I bought some calibration fluid for my refractometer and i just check it before i use it now. Very easy to do.

 

[grouper therapy]

peaches7412;736909 wrote: I use a instant ocean refractometer, and it is always off by 0.003(example it reads 1.023, but is actually 1.026). I just bring it to the fish store occasionally and make sure it keeps reading like that.

Assuming the fish store"s is calibrated correctly

 

[cr500_af]

grouper therapy;736947 wrote: Assuming the fish store"s is calibrated correctly

True dat!

I'd think the easiest answer would be to pick up a small packet of calibration fluid... if two different test solutions say your refract is right, then it's right.

 

[jhutto]

I have a refractometer, the calibration fluid and the new electronic one that is calibrated. I love it. You are welcome to bring some water along with your meter. Off exit 11 on ga 400

 

[morganatlanta]

So my salinity is somewhere between 1.020 and 1.027... Good to know...
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[cr500_af]

MorganAtlanta;736966 wrote: So my salinity is somewhere between 1.020 and 1.027... Good to know...

Figure out which, and throw at least one away.

 

[morganatlanta]

It was actually 1.023, assuming my LFS's system was really 1.0255 like they said. I should throw them both away, but instead I put a mark on each of them at 1.025.

 

[grouper therapy]

Two things most people don't do when using Hydrometers: Rinse them with fresh after and before using them and make sure no bubbles are attached to the swing arm. then the readings are over the place. When properly used and maintained I trust them more than a refractometer. 99.999 % of the time that is the problem.

 

[cr500_af]

grouper therapy;736993 wrote: Two things most people don't do when using Hydrometers: Rinse them with fresh after and before using them and make sure no bubbles are attached to the swing arm. then the readings are over the place. When properly used and maintained I trust them more than a refractometer. 99.999 % of the time that is the problem.

I agree that they are reliable, I've just seen few that actually read the right number. If you can see how much error there is, of course you can adjust your target number to compensate. Curious, though, why do you trust a refractormeter less? Just the angle of having to be calibrated from time to time?

 

[ralph atl]

just get some pinpoint calibration fluid for like five bucks or sooo....simple and no worries.

 

[morganatlanta]

I just can't believe that hydrometers are sold so out of whack. Their only job is to measure salinity. The older one, which reads about .003 low, actually has a little tab on the swing arm that says "Certified Calibration". The newer one, which reads about 0.004 high, does not. I guess Coralife gave up all pretense about being accurate in the newer model. They do both read consistently, just way off.

 

[grouper therapy]

cr500_af;736996 wrote: I agree that they are reliable, I've just seen few that actually read the right number. If you can see how much error there is, of course you can adjust your target number to compensate. Curious, though, why do you trust a refractormeter less? Just the angle of having to be calibrated from time to time?

Exactly , They are even more susceptible to error if not properly cleaned and maintained. You can accidentally bump them too hard and they need calibration. I'd like to gather some hydros and do a little experiment with them. I

 

[cr500_af]

I learned that the hard way once. My Brute is in the laundry room, and I kept my refractometer on the shelf. Apparently the vibration from the spin cycle was enough to throw it out. Started keeping it in a drawer (always in the case) and it has stayed dead on ever since.

 

[demifelix]

Thanks all. I think I'll bring water to my LFS to check it out first and get another calibrating solution next.