don't trust hydrometers!!
- Thread starter ci11337
- Start date
sepulatian
Moderator
Excellent one
Swing arm hydrometers are terribly inaccurate. Glass hydrometers are better, and better still, are refractometers.
Swing arm hydrometers are terribly inaccurate. Glass hydrometers are better, and better still, are refractometers.
reefkprz
Active Member
I agree in a way. swing arm hydrometers can be terribly innacurate. but using one that has been calibrated off a refractometer is OK, just make sure you get it calibrated, keep it calibrated (check it often) and rinse it after every use. I still use a swing arm hydrometer for most of my checking, its quicker. but I also rinse it EVERYTIME, and make sure its accurate every week or two.
sepulatian
Moderator
Originally Posted by reefkprZ
http:///forum/post/2605805
I agree in a way. swing arm hydrometers can be terribly innacurate. but using one that has been calibrated off a refractometer is OK, just make sure you get it calibrated, keep it calibrated (check it often) and rinse it after every use. I still use a swing arm hydrometer for most of my checking, its quicker. but I also rinse it EVERYTIME, and make sure its accurate every week or two.
Reef, how do you calibrate a swing arm hydrometer? I haven't used one in quite some time. I don't recall there being anything to adjust. I had a Deep Six one.
http:///forum/post/2605805
I agree in a way. swing arm hydrometers can be terribly innacurate. but using one that has been calibrated off a refractometer is OK, just make sure you get it calibrated, keep it calibrated (check it often) and rinse it after every use. I still use a swing arm hydrometer for most of my checking, its quicker. but I also rinse it EVERYTIME, and make sure its accurate every week or two.
Reef, how do you calibrate a swing arm hydrometer? I haven't used one in quite some time. I don't recall there being anything to adjust. I had a Deep Six one.
ci11337
Active Member
Originally Posted by reefkprZ
http:///forum/post/2605805
I agree in a way. swing arm hydrometers can be terribly innacurate. but using one that has been calibrated off a refractometer is OK, just make sure you get it calibrated, keep it calibrated (check it often) and rinse it after every use. I still use a swing arm hydrometer for most of my checking, its quicker. but I also rinse it EVERYTIME, and make sure its accurate every week or two.
excellent advice, basically, to calibrate a hydrometer you see how inaccurate it is by comparing it to something that is right on. for example, my hydrometer reads 0.005 to high. So when my hydrometer reads 1.020 the water is actually closer to 1.025.
http:///forum/post/2605805
I agree in a way. swing arm hydrometers can be terribly innacurate. but using one that has been calibrated off a refractometer is OK, just make sure you get it calibrated, keep it calibrated (check it often) and rinse it after every use. I still use a swing arm hydrometer for most of my checking, its quicker. but I also rinse it EVERYTIME, and make sure its accurate every week or two.
excellent advice, basically, to calibrate a hydrometer you see how inaccurate it is by comparing it to something that is right on. for example, my hydrometer reads 0.005 to high. So when my hydrometer reads 1.020 the water is actually closer to 1.025.
sepulatian
Moderator
Originally Posted by ci11337
http:///forum/post/2606323
excellent advice, basically, to calibrate a hydrometer you see how inaccurate it is by comparing it to something that is right on. for example, my hydrometer reads 0.005 to high. So when my hydrometer reads 1.020 the water is actually closer to 1.025.
Ah, gotcha. I was wondering how that would work. That seems like it would kind of be a pain to a new hobbyist who may not have a refractometer to compare it to though. They would have to bring water the their LFS to have it tested and then compare it to the hydrometer reading.
http:///forum/post/2606323
excellent advice, basically, to calibrate a hydrometer you see how inaccurate it is by comparing it to something that is right on. for example, my hydrometer reads 0.005 to high. So when my hydrometer reads 1.020 the water is actually closer to 1.025.
Ah, gotcha. I was wondering how that would work. That seems like it would kind of be a pain to a new hobbyist who may not have a refractometer to compare it to though. They would have to bring water the their LFS to have it tested and then compare it to the hydrometer reading.
reefkprz
Active Member
I just take the hydrometer with me instead of lugging water, but thats just me. then I mark on it my target zone with a sharpie or scratch it into the side.
I had one that was 0.004 off when I got it and it slowly became more accurate over time, untill it was dead on and stayed correct for almost a year before my dogs ate it.
I had one that was 0.004 off when I got it and it slowly became more accurate over time, untill it was dead on and stayed correct for almost a year before my dogs ate it.
mmm33732
Member
Agreed. I had 2 good ones that always agreed that my salt level was 1.025. I noticed I was getting much more salt creep that I had a year ago, so I suspected something was off. I bought a refractometer, calibrated it and checked and my levels were really 1.031. I had this confirmed later with someone else who gotten the same results with my water.
mudplayerx
Active Member
There really is no excuse to use a swing-arm hydrometer this day and age. They usually run about $10 at a local pet store. You can find refractometers online now for $40. Do yourself a favor, save the extra $30 and get a refractometer.
ps- I know I just advised against swing arm hydrometers, but I did use one in the past for 2 years and never had any salinity-related issues. Just keep in mind they CAN be inaccurate.
ps- I know I just advised against swing arm hydrometers, but I did use one in the past for 2 years and never had any salinity-related issues. Just keep in mind they CAN be inaccurate.
kirkland
Member
we used a glass hydrometer when we had an aggressive fish-only tank. when we switched to a reef tank, we bought a refractometer. a friend who has had a saltwater tank for years, goes to the big seattle aquarium
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, visits LFS frequently, etc had never heard of a refractometer and he's too cheap to buy one.
[hr]
, visits LFS frequently, etc had never heard of a refractometer and he's too cheap to buy one.
sepulatian
Moderator
Glass hydrometers are pretty accurate. The refractometer is still the way to go IMO
sepulatian
Moderator
Originally Posted by aquaferg
http:///forum/post/2620334
will any reflectometer work? I found one on a industrial supply site that I have used for other things that was about $40 and they have local stores. Said you could use it for battery fluid and antifreeze. would it work? Looked just like the ones we use...
Mine came with recipes. It was for anything salt related, including a margarita. I bought it from this site. Does it have the full scale of salinity and specific gravity? From zero to over 40?
http:///forum/post/2620334
will any reflectometer work? I found one on a industrial supply site that I have used for other things that was about $40 and they have local stores. Said you could use it for battery fluid and antifreeze. would it work? Looked just like the ones we use...
Mine came with recipes. It was for anything salt related, including a margarita. I bought it from this site. Does it have the full scale of salinity and specific gravity? From zero to over 40?
natclanwy
Active Member
Originally Posted by aquaferg
http:///forum/post/2620334
will any reflectometer work? I found one on a industrial supply site that I have used for other things that was about $40 and they have local stores. Said you could use it for battery fluid and antifreeze. would it work? Looked just like the ones we use...
These won't work, the range is not correct if I remember right it does not go low enough.
I cannot see how a swing arm hydrometer can be faster than a refractometer, I can have a reading on my refractometer before I could fill a hydrometer with water and then after that you have tap on it to make sure all of the air bubbles have been removed not to mention I would get a slightly different reading each time I used it.
http:///forum/post/2620334
will any reflectometer work? I found one on a industrial supply site that I have used for other things that was about $40 and they have local stores. Said you could use it for battery fluid and antifreeze. would it work? Looked just like the ones we use...
These won't work, the range is not correct if I remember right it does not go low enough.
I cannot see how a swing arm hydrometer can be faster than a refractometer, I can have a reading on my refractometer before I could fill a hydrometer with water and then after that you have tap on it to make sure all of the air bubbles have been removed not to mention I would get a slightly different reading each time I used it.
sepulatian
Moderator
Originally Posted by natclanwy
http:///forum/post/2620363
These won't work, the range is not correct if I remember right it does not go low enough.
I cannot see how a swing arm hydrometer can be faster than a refractometer, I can have a reading on my refractometer before I could fill a hydrometer with water and then after that you have tap on it to make sure all of the air bubbles have been removed not to mention I would get a slightly different reading each time I used it.
I don't really see how it is quicker either
My refractometer takes seconds, and I know that it is correct.
http:///forum/post/2620363
These won't work, the range is not correct if I remember right it does not go low enough.
I cannot see how a swing arm hydrometer can be faster than a refractometer, I can have a reading on my refractometer before I could fill a hydrometer with water and then after that you have tap on it to make sure all of the air bubbles have been removed not to mention I would get a slightly different reading each time I used it.
I don't really see how it is quicker either
My refractometer takes seconds, and I know that it is correct.
mudplayerx
Active Member
Originally Posted by sepulatian
http:///forum/post/2620369
I don't really see how it is quicker either
My refractometer takes seconds, and I know that it is correct.
Refractometers work as soon as you drip the water on them.
http:///forum/post/2620369
I don't really see how it is quicker either
My refractometer takes seconds, and I know that it is correct.
Refractometers work as soon as you drip the water on them.
tomato clown
Member
Originally Posted by mudplayerx
http:///forum/post/2620469
Refractometers work as soon as you drip the water on them.
Technically with any refractometer it has to be adjusted properly to begin with. If you buy one from lets say website A, they may have adjusted it wrong, but the one from Website B can be spot on. If there is debris floating in the water that is
[hr]
to the eye, the refractometer can be off as well.
I used to use these things on different blood tests when checking cell counts and it doesn't take very much to get an "off reading". However, even as "off" as they can be, they would still have a better reading than a swing-arm.
The only downside on the refractometer is how you clean it. If it's not cleaned properly then the reading will always be wrong.
http:///forum/post/2620469
Refractometers work as soon as you drip the water on them.
Technically with any refractometer it has to be adjusted properly to begin with. If you buy one from lets say website A, they may have adjusted it wrong, but the one from Website B can be spot on. If there is debris floating in the water that is
[hr]
to the eye, the refractometer can be off as well.
I used to use these things on different blood tests when checking cell counts and it doesn't take very much to get an "off reading". However, even as "off" as they can be, they would still have a better reading than a swing-arm.
The only downside on the refractometer is how you clean it. If it's not cleaned properly then the reading will always be wrong.