hydrometer question

gkotlin

gkotlin

Member
More or less. Yes. Just add it slowly and check it again with they hydrometer. In my tank, it takes much less "regular" water to lower salinity than it does to add saltwater to incease salinity.
 
amandal

amandal

Member
If it's brand new, did you calibrate the hydrometer with fresh RO water before you started? Some models come with a tiny screwdriver and a calibration screw so you can zero the scale while reading fresh water.
 
1journeyman

1journeyman

Active Member
Originally Posted by brrlong
yes im sure its reading correctly, its a new tank, and new hydrometer
just bought it thanks guys :)
Hydrometers are notoriously inaccurate. Always good to get a second opinion from a LFS.
 
aw2

aw2

Active Member
Originally Posted by 1journeyman
Hydrometers are notoriously inaccurate. Always good to get a second opinion from a LFS.
Once you calibrate them, though, they're basically the most accurate instrument you can buy, to test your salinity/SG.
 
murph

murph

Active Member
Your hydrometer is most likely inaccurate. If its new make sure to let it "cure". Fill it with some tank water and let it sit for at least 24 hours. When taking a reading maker sure no micro bubbles are attached to the swing arm. After all this it will probably still give an inaccurate reading.
Buy a refractometer for more accurate results or find someone or an lfs with one and test your water. When you know for sure what your SG is using a refractometer you can then do the math plus or minus using a hydrometer.
For example my hydrometer was reading 1.025. When I compared this to a trusted LFS using a refractometer I found my hydrometer was reading .005 high. So with my hydrometer to attain a 1.025 SG I need to mix water that reads 1.020.
I have since checked and double check and the good news seems that hydrometers will give consistent but inaccurate readings. So after you find the right adjustment for the scale you should be good to go.
 
chipmaker

chipmaker

Active Member
I don;t know about adjusting any hydrometer, as none that I have ever seen was adjustable. Refractometers yes, most are calibrateable. ANother thing with hydrometers (swing arm type) is they need to be on a perfectly flat surface that is level, not merely heled up and looked at. Just a slight tip on way or the other can make a big difference in its readings. As much as folks hate swingarm types, if you have one that works and you have it verified, there is nothing wrong with using it......but right out of the package and not bumped up against a known in cal device its a crap shoot.
 
1journeyman

1journeyman

Active Member
Originally Posted by AW2
Once you calibrate them, though, they're basically the most accurate instrument you can buy, to test your salinity/SG.
Really? I don't trust them at all...
 
aw2

aw2

Active Member
HAHAHAHA....sorry, guys. It was after 5am, when I posted up above, talking about how accurate hydometers are.
The whole time I was typing, I was thinking refractometers...not hydrometers.

Dont look at me...it was late.
 
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