Crummy Hydrometer WAY off !!!!

[hot883]

Ok, so I was using a crummy swingarm plastic hydrometer. When I was getting my water tested at the LFS I was told that it was at 1.030 S.G. when my plastic swingarn crappy thing showed me 1.024-25. They were using a plastic one too, so not really concerned.
Well, MORAL of the story is, I recieved my refractometer yesterday and got it calibrated with distilled water today. Wow; tested my water and sure enough, 1.030.
I needed to do a water change anyway, so I will do that VERY SLOWLY, over a couple of days bringing it down to where it needs to be.
Just thought that i would share.

 

[diane4]

I concur with you. I have never relied on a hydrometer. I have dunked the thing in the tank 5 times in a row and got a different reading each time. They are completely unreliable and unpredictable.
Refractometer is the safest bet. Also, they do sell on the internet calibration fluid to 35ppt salinity, which equates to the appx 1.025 SG.

 

[hot883]

Originally Posted by diane4
I concur with you. I have never relied on a hydrometer. I have dunked the thing in the tank 5 times in a row and got a different reading each time. They are completely unreliable and unpredictable.
Refractometer is the safest bet. Also, they do sell on the internet calibration fluid to 35ppt salinity, which equates to the appx 1.025 SG.
My directions said to use distilled water, should I look for the calibration fluid? Is there any difference?

 

[mirandaj]

I noticed when testing the water with the swing arm you can set it on a levle/flat (some houses are not levle) surface and walk away. And every time it should be accurate.

 

[hot883]

Originally Posted by MirandaJ
I noticed when testing the water with the swing arm you can set it on a levle/flat (some houses are not levle) surface and walk away. And every time it should be accurate.
One day you will be surprised at how unaccurate they are.

 

[chipmaker]

I bumped my swing arm hydrometer up against my refractometer and its like the thickness of a line difference between the hydrometers reading and what the refractometer reads......Its more than close enough. My water stays in the same general temp range 79.7 to 80.5 so temp fluctuations is not going to make it change any amount that I would need to be concerned with...As MirandaJ stated though, it has to be placed on a level surface or it will show the wrong SG. I sure do not know why everyone is so down on hydrometers........bump one to a refractometer and check it, and if its right there is no reason it will go out of calibration if its not abused.......

 

[mirandaj]

its all scientific, and the salt is measured on gravity. You take a levle go around your place and find a levle surface, then measure the salt in your tank with the hydrometer. I know it might take longer but its less money. Also if you have bubbles on the swing arm it will effect it cause air rises and gravity pulls down so there is a conflict in the reading when that happens. I guess its patience verses technology.

 

[reeferdc]

i agree

 

[airforceb2]

Also, make sure you season your hydrometer before the first use. I know coralife requires you to let the hydrometer sit for 24 hours full of salt water. This will allow the swing arm to absorb salt and give accurate readings.

 

[sinner's girl]

Crummy Hydrometer WAY off !!!!
duh! Mine gave me so much trouble. I use just a regular swing arm thing, it's way better than the hydrometer.
I was adding salt to raise sg, cause the hydrometer said I was low, for some reason I thought they were better than the plain swing are things. I have the fish store test my water with thier hydrometer, he got a different reading, like .03 off. So he tested it with the refractormeter. ugh. the hydrometer went bye bye. I was told some brands are better, but I followed the instruction, got rid of all bubbles, it was on a flat surface and I'd walk away and wait. Ugh. Now I know how much my swing off is off (.001) so I'm good.

 

[hot883]

Originally Posted by Sinner's Girl
duh! Mine gave me so much trouble. I use just a regular swing arm thing, it's way better than the hydrometer.
I was adding salt to raise sg, cause the hydrometer said I was low, for some reason I thought they were better than the plain swing are things. I have the fish store test my water with thier hydrometer, he got a different reading, like .03 off. So he tested it with the refractormeter. ugh. the hydrometer went bye bye. I was told some brands are better, but I followed the instruction, got rid of all bubbles, it was on a flat surface and I'd walk away and wait. Ugh. Now I know how much my swing off is off (.001) so I'm good.
My hydrometer is a swing arm. Did I misunderstand that or ?

 

[sinner's girl]

no, i have something that's not a hyrdometer, but it's a swing arm...SeaTest Full Range Speafic Gravity Test or something.

 

[diane4]

Originally Posted by hot883
My directions said to use distilled water, should I look for the calibration fluid? Is there any difference?
I haven't heard of using distilled water to calibrate because distilled water has no salt. The calibration fluid is set perfectly to 35 ppt and you can adjust, if necessary your refractometer to that.

 

[carpe_diem]

the coralife brand is good for the swingarm type

 

[hot883]

Originally Posted by diane4
I haven't heard of using distilled water to calibrate because distilled water has no salt. The calibration fluid is set perfectly to 35 ppt and you can adjust, if necessary your refractometer to that.
You put the distilled water in and adjust the line to zero if needed and then it's set.

 

[diane4]

Originally Posted by hot883
You put the distilled water in and adjust the line to zero if needed and then it's set.
I question that, because in order to check if the refractometer is acurately measuring salt content, doesn't there have to be salt present? One would think?
I bought salinity solution. It is at 35 ppt. Check is out online.

 

[jacknjill]

Originally Posted by Sinner's Girl
no, i have something that's not a hyrdometer, but it's a swing arm...SeaTest Full Range Speafic Gravity Test or something.
a hydrometer has a swing arm. he is saying that his hydrometer sucks so he got a refractomter that is great

 

[hot883]

Originally Posted by JacknJill
a hydrometer has a swing arm. he is saying that his hydrometer sucks so he got a refractomter that is great

 

[shnabbles]

Yes you can use distilled water to calibrate a refractometer... Put the drops on the the lense and adjust the nob untill it becomes 0
Refractometers are the only way to go if you plan on having a successul reef.

 

[hot883]

Originally Posted by diane4
I question that, because in order to check if the refractometer is acurately measuring salt content, doesn't there have to be salt present? One would think?
I bought salinity solution. It is at 35 ppt. Check is out online.
With the distilled water, you adjust the line to zero and ANY amount of sw then tested will come to the correct S.G. level.