Hydrometer

S

steve620

Guest
I'm using a Red Sea Hydrometer, I keep it in the tank all the time everything was find till this morning when I checked it the reading was way down. The fish all seem to be acting normal. Is there a better Hydrometer to get or this normal to get different readings like this?
 
flower

flower

Well-Known Member
Quote:
Originally Posted by steve620 http:///t/388205/hydrometer#post_3421948
I'm using a Red Sea Hydrometer, I keep it in the tank all the time everything was find till this morning when I checked it the reading was way down. The fish all seem to be acting normal. Is there a better Hydrometer to get or this normal to get different readings like this?
Have you topped off the water? You want to keep the same water level. Add freshwater to bring up the water level to what it was at first. Water evaporates but salt doesn't so only add the water.
The SG should climb not drop. I used a Red Sea hydrometer for 6 years. However I never just left it in the tank, it may be clogged with salt. Take it out and rinse it under warm water.
Hydrometers are not all that accurate, but they do provide a measure of SG good enough to match up for water changes.
 
red tiger

red tiger

Member
I am using an Instant Ocean and i get different readings with in my 50 gallon. Do not know why?
I have a 55 gal barrel where i pre mix my salt with water circulating with a powerhead, and my readings are stable at 1.025.
But in my DT there 1.023 to 1.029!
 
flower

flower

Well-Known Member
Quote:
Originally Posted by Red Tiger http:///t/388205/hydrometer#post_3421975
I am using an Instant Ocean and i get different readings with in my 50 gallon. Do not know why?
I have a 55 gal barrel where i pre mix my salt with water circulating with a powerhead, and my readings are stable at 1.025.
But in my DT there 1.023 to 1.029!
You couldn't pay me enough to trust a deep six instant ocean hydrometer...get a refractometer or Red Sea hydrometer
 
slice

slice

Active Member
If you continue to use a hydrometer, take a water sample to your LFS for a refractometer reading. Compare that reading to your hydrometer's to see how much your hydrometer is off.
I did that when using a hydrometer and found it's reading was off by +.002. From then on, I took .002 off my hydrometer reading to get a more accurate notion of my SG.
Note that hydrometer readings will drift over time, so I would advise to compare to a refractometer reading every 6 months or so.
The peace of mind one gets from a calibrated refractometer is priceless.
 
tur4k

tur4k

Member

Micro bubbles sticking to the needle can cause false readings. My first post here was "OMG I think I nuked my tank" because my hydrometer had air sticking to the needle and was reading 1.032. I threw it in the trash and bought a refractometer as soon as I figured out what was going on.
 
slice

slice

Active Member
Quote:
Originally Posted by steve620 http:///t/388205/hydrometer#post_3422033
Are there any brand refractometer I should get ?
There are many available, just read the reviews for the differing brands. Some reviews say this one or that one needs calibrating more often (I feel the need to calibrate mine most every time I do a test, not hard, takes 2 minutes). There are many reliable units for $49.
 
flower

flower

Well-Known Member
Quote:
Originally Posted by Slice http:///t/388205/hydrometer#post_3421995
If you continue to use a hydrometer, take a water sample to your LFS for a refractometer reading. Compare that reading to your hydrometer's to see how much your hydrometer is off.
I did that when using a hydrometer and found it's reading was off by +.002. From then on, I took .002 off my hydrometer reading to get a more accurate notion of my SG.
Note that hydrometer readings will drift over time, so I would advise to compare to a refractometer reading every 6 months or so.
The peace of mind one gets from a calibrated refractometer is priceless.
I had my Red Sea hydrometer 6 years, then for some reason the thing said my SG was 1.040 so I ordered the refractometer...the little red sea was reading right on the money. To this day I'm not sure why my SG went so far off. I tossed out the hydrometer now that I have the new gizmo. I have not had to recalculate since I purchased it almost a year ago. It just says Marine Depot Refractometer on the box it cost around $50.00 if memory serves.
 
slice

slice

Active Member
Quote:
Originally Posted by Flower http:///t/388205/hydrometer#post_3422090
I had my Red Sea hydrometer 6 years, then for some reason the thing said my SG was 1.040 so I ordered the refractometer...the little red sea was reading right on the money. To this day I'm not sure why my SG went so far off. I tossed out the hydrometer now that I have the new gizmo. I have not had to recalculate since I purchased it almost a year ago. It just says Marine Depot Refractometer on the box it cost around $50.00 if memory serves.
In all fairness, I've had 2 hydrometers, one Deep Six, which I used for ~8 months and a Red Sea that I won as a door prize. I gave both away.
The Deep Six is the one that was off by +.002, the Red Sea was dead on initially.
I calibrate my refractometer every time I take a reading. The last couple of times it has been dead on, but why use faith when you can use calibration solution? If you haven't calibrated in a year, how far are you off????
$5 says you are off by at least .002.
 
flower

flower

Well-Known Member
Quote:
Originally Posted by Slice http:///t/388205/hydrometer#post_3422095
In all fairness, I've had 2 hydrometers, one Deep Six, which I used for ~8 months and a Red Sea that I won as a door prize. I gave both away.
The Deep Six is the one that was off by +.002, the Red Sea was dead on initially.
I calibrate my refractometer every time I take a reading. The last couple of times it has been dead on, but why use faith when you can use calibration solution? If you haven't calibrated in a year, how far are you off????
$5 says you are off by at least .002.
LOL....I use RO water...if it is on the 0 then no need to calibrate...it's all set. I may not of had to calibrate in a year, that does not mean I didn't check it. Oh and I always clean it off and store it in it's container keeping it clean.
 
slice

slice

Active Member
Quote:
Originally Posted by Flower http:///t/388205/hydrometer#post_3422104
LOL....I use RO water...if it is on the 0 then no need to calibrate...it's all set. I may not of had to calibrate in a year, that does not mean I didn't check it. Oh and I always clean it off and store it in it's container keeping it clean.
AH HAH!!
You DO calibrate! You use RO instead of 35ppt solution. You owe me $5.
-put on my account...
 
bang guy

bang guy

Moderator
Calibrating a Chinese built refractometer with RO water will not ensure accuracy. In my humble opinion it should be calibrated with a 35ppt solution.
 
flower

flower

Well-Known Member
Quote:
Originally Posted by Slice http:///t/388205/hydrometer#post_3422109
AH HAH!!
You DO calibrate! You use RO instead of 35ppt solution. You owe me $5.
-put on my account...
LOL.....My post said I have not had to REcalibrate...I haven't. Nor is it off by 002 so I don't owe you anything. To calibrate you take the little screwdriver and make it go to 0 with RO water, which is 0 SG. I did it once and it has been fine ever since. I keep double checking but it remains stable.
I never heard of any solution of 35ppt????
 
bang guy

bang guy

Moderator
Flower, you should find a 35ppt calibration fluid. You only need to do it once. After that you can use RO. Once you calibrate at exactly 35ppt you just need to take another reading with RO water and check if it's off-zero. If it's off just note by how much and then you're all set.
 
snakeblitz33

snakeblitz33

Well-Known Member
Quote:
Originally Posted by Bang Guy http:///t/388205/hydrometer#post_3422434
Flower, you should find a 35ppt calibration fluid. You only need to do it once. After that you can use RO. Once you calibrate at exactly 35ppt you just need to take another reading with RO water and check if it's off-zero. If it's off just note by how much and then you're all set.
+1
 
flower

flower

Well-Known Member
Quote:
Originally Posted by SnakeBlitz33 http:///t/388205/hydrometer#post_3422448
+1
Quote:
Originally Posted by Bang Guy http:///t/388205/hydrometer#post_3422434
Flower, you should find a 35ppt calibration fluid. You only need to do it once. After that you can use RO. Once you calibrate at exactly 35ppt you just need to take another reading with RO water and check if it's off-zero. If it's off just note by how much and then you're all set.
Where on Earth does one get such a solution? And why in the world, since it only needs to be done 1 time...do they not sell it with the refractometer?????
 
bang guy

bang guy

Moderator
Quote:
Originally Posted by Flower http:///t/388205/hydrometer#post_3422506
Where on Earth does one get such a solution? And why in the world, since it only needs to be done 1 time...do they not sell it with the refractometer?????
The better refratometers come with a 35ppt calibration solution.
You can find it at many online stores and auction sites.
You may be spot on but if you get a 35ppt solution then you will know for sure. That said, being off 0.5ppt isn't really all that important unless you are attempting hyposalinity.
 
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