Hydrometer

[Hez]

Hi All,

I just set-up my 12g nanocube 4 days ago. I bought two different Hydrometers. One is from Instant Ocean and the other from Deep Six which takes measurements from below the waters surface.

The Deep Six Hydrometer records SG at 1.020 while the other records my SG at 1.024.

Is there any explanation for this and which is hydrometer has historically been more accurate?

Thanks for your help.

 

[Anonymous]

Yes there is an explanation - those floaty thing hydrometers are notoriously inaccurate. Your comparison of the two confirms that fact.

I would invest in a refractometer, easier to read and much more accurate. Especially in a tank as small as yours, where little errors can lead to big problems.

 

[Sugar Magnolia]

Check out this thread. http://www.reefs.org/phpBB2/viewtopic.php?t=63522

 

[Anonymous]

Get a refractometer! The investment is more than worth it IMHO and if you decide to get out of the game, they are VERY resellable as long as you take care of them.

 

[Tackett]

refracts are the bomb dude.

 

[dodo99]

I just purchased a Deep Six two days ago as well - my Instant Ocean hydro cracked the other day, so it couldn't hold water anymore. I have the exact same results. The IO shows 0.03 to 0.04 difference (lower).

Can either of them be accurate? I let the Deep-Six filled with SW for 24hrs like it said on the box... I recently added an LTA, and I'm trying to get the salt content closer to 1.025. From what I've read, the LTA's like a higher salt content, correct?

DoDo

 

[Anonymous]

Find someone, or an LFS with a refractometer, and go visit with either of you float hydrometers. Make sure the refractometer is calibrated, and test some water at the level you like (1.025 is what I like), and mark that level on your hydrometer. Now your hydrometer is calibrated!

 

[Tackett]

Find someone, or an LFS with a refractometer, and go visit with either of you float hydrometers. Make sure the refractometer is calibrated, and test some water at the level you like (1.025 is what I like), and mark that level on your hydrometer. Now your hydrometer is calibrated!

8O simple genious that I would have never thought of....thats a great idea.

 

[Anonymous]

Find someone, or an LFS with a refractometer, and go visit with either of you float hydrometers. Make sure the refractometer is calibrated, and test some water at the level you like (1.025 is what I like), and mark that level on your hydrometer. Now your hydrometer is calibrated!

That will work. The floaty one will still have some issues though, like unseen bubbles on the swing arm throwing off the reading.

 

[Anonymous]

Find someone, or an LFS with a refractometer, and go visit with either of you float hydrometers. Make sure the refractometer is calibrated, and test some water at the level you like (1.025 is what I like), and mark that level on your hydrometer. Now your hydrometer is calibrated!

That will work. The floaty one will still have some issues though, like unseen bubbles on the swing arm throwing off the reading.

Sure. IME, even with those you are getting close enough (although I try to minimize them) - which is really all we can hope for with the hobby level testing devices.
I actually find the refractometer to be a PITA because it needs to be calibrated every time you use it. I pull it out a couple times a year and check the floaties.

 

[Anonymous]

Find someone, or an LFS with a refractometer, and go visit with either of you float hydrometers. Make sure the refractometer is calibrated, and test some water at the level you like (1.025 is what I like), and mark that level on your hydrometer. Now your hydrometer is calibrated!

8O simple genious that I would have never thought of....thats a great idea.

I wish I could take credit for it!

 

[Anonymous]

I actually find the refractometer to be a PITA because it needs to be calibrated every time you use it.

Weird, I check mine only a couple times a year or so, last time it was still dead on. I wonder what makes ours behave so differently.

BTW I don't get a kickback on refractometer sales or anything. I realize the cost difference may not make it worthwhile for a lot of people.

 

[Sugar Magnolia]

I actually find the refractometer to be a PITA because it needs to be calibrated every time you use it.

Weird, I check mine only a couple times a year or so, last time it was still dead on. I wonder what makes ours behave so differently.

Same here, I just checked mine for calibration last week and it was still dead on after about 6 months.

 

[Anonymous]

It think as the calibration screw gets rusty, it stop slipping!

Either way, I find the refractometer calibrated float hydrometer easier/faster to use on a regular basis. YMMV.

 

[Anonymous]

Well surprisingly my swing arm hydrometer read the same as my Refractometer..However with my refractometer, I trust that far more now than I would a hydrometer...the link to the above thread is the refractometer I just received..It is a nice little device, you wont regret it...It runs about 45 bucks, 51.36 shipped..

 

[Anonymous]

I have a swing arm hydrometer that I calibrated against a refractometer. It is repeatable, but it was off by quite a bit.