the importance of a refractometer

Reverend Reefer · 11/30/2009, 04:48 PM

well, as some of you might know, i used to have a fish problem - i couldn't keep any fish alive. i tried everything under the sun and many thanks to everyone's suggestions. in the end, due to sheer luck, i solved the problem....

it was my specific gravity! i was using several different types of hydrometers: ones with moving arm bars, and one that floats and has a thermometer in it. these always gave me perfect readings.

then one day, i bought a refractometer and that silly little thing that i didn't want to spend money on previously showed my SG to be over 1.032!!!! so i started adding more top-off water daily to dilute my water and now, im happy to say, i have fish!!

i keep mostly LPS corals and i guess they were pretty tolerant of the salty water but i just wanted to post for my fellow newbies, GET A REFRACTOMETER! they are worth it.

kimber45 · 11/30/2009, 04:56 PM

not disagreeing with you but the funny thing is i have a 10+ year old hydrometer that to this day reads within .005 of my refractometer.

Madratter · 11/30/2009, 05:03 PM

Well I could name names but I bought I so called calibrated Hydrometer that was no where close to the refractometer. My refractometer was reading .003 higher. And getting all the air bubbles off to get a "accurate" reading with the hydrometer was a royal pain. I have spent "some" money in this hobby I wish I had back, but a refractometer was money very well spent.

Madratter · 11/30/2009, 05:04 PM

Quote:

Originally Posted by kimber45

not disagreeing with you but the funny thing is i have a 10+ year old hydrometer that to this day reads within .005 of my refractometer.

I'm hoping (and think) you mean .0005. There is a vast difference between water at 1.023 and 1.028.

C3gear · 11/30/2009, 05:06 PM

My refractometer was one of the best investments after my ro-di unit and skimmer.

RussR19146 · 11/30/2009, 05:21 PM

Just bought a refractometer myself and while the numbers seem close to the swing arm hydrometer the peace of mind is well worth it

my best purchases so far - temperature controller, refractometer and phosphate removal system (after the fish and coral of course)

dwculp · 11/30/2009, 05:30 PM

Yep - I will NEVER be without a refractometer ever again. I had about 3 swing arm hydrometers and all three read different readings. I just took an average. Once I got the refractometer and calibrated it I was stunned at how far off the hydrometers were.

I consider a good refractometer essential equipment.

Mrbeachbum2 · 11/30/2009, 05:38 PM

Quote:

Originally Posted by dwculp

Yep - I will NEVER be without a refractometer ever again. I had about 3 swing arm hydrometers and all three read different readings. I just took an average. Once I got the refractometer and calibrated it I was stunned at how far off the hydrometers were.

I consider a good refractometer essential equipment.

What one do you have?

cloak · 11/30/2009, 06:36 PM

You can get around not having a refractometer is this hobby very easily. Just like you can not running any carbon or a refuge, using all tap water, incorperating bioballs, etc. It's not necessarily the equipment that's the problem, human error is a big factor. Aside from me breaking my $5.99 floating glass hydrometer sometiimes, replacing it with the same one has been working fine for almost 13 years.

der_wille_zur_macht · 11/30/2009, 06:41 PM

IMHO the thread title should be "the importance of accurate salinity readings." Hydrometers get a bad rep on here, and while it's easy to get bad readings with one, it's *almost* as easy to get bad readings with a refractometer.

Regardless of which tool you use, it's just a tool - it's not going to solve problems for you, or give you good results, unless you: a) know how to use it correctly, and b) know how to calibrate it, or at least check it for accuracy.

In other words, I don't really think it matters which type of tool you use. Just pick a tool, then make sure you're using it correctly. Blindly assuming that a refractometer is "better" than any other type of measuring tool, and using one without calibrating or understanding proper procedure, is just as bad as using any other tool poorly.

spleify · 11/30/2009, 06:41 PM

IMO a refractometer is a must.

I will never be without one either

Big Country_IL · 11/30/2009, 06:46 PM

I switched to a refractometer after about 6 months and wish I would have earlier. Just added a temp controller now and also wish I would've started with it. Hydrometers do work, but I prefer the refractometer.

floridazooguy · 11/30/2009, 07:02 PM

I agree both work but I also use both to check so im sure.

Jtro · 11/30/2009, 07:13 PM

My refractometer was slightly off purchased some calibration solution and its good as new not sure if it was off since it was new or the kids may have adjusted for me.Will keep a eye on it.

Juruense · 11/30/2009, 07:20 PM

I use a floating glass tube hydrometer, it is a little off but I know that because I had it calibrated to a known good refractometer at the LFS to see exactly how much it was off. It reads a little low but I know that so it is ok I would prefer to have a super accurate measuring device however.

sam11909 · 11/30/2009, 08:04 PM

Same thing happened to me, didn't know why everything kept dieing for no reason.

joel g · 11/30/2009, 09:34 PM

I have been trying to buy one for a while but every time I go to buy one I end up bringing home a couple of frags instead

monotreme_man · 12/01/2009, 04:53 AM

der wille

how does one screw up a refractometer reading?

sometimes i find it hard to see the line, but simply redoing the procedure
normally makes it visible. when i started out, i would try taking five
readings in a row in order to check reproducibility but never found
skew readings. but your comment has made me worried; are there
failure modes i haven't anticpated?

Lightsluvr · 12/01/2009, 04:56 AM

Quote:

Originally Posted by Madratter

I'm hoping (and think) you mean .0005.

Maybe not...

LL

mnchartier · 12/01/2009, 08:20 AM

Quote:

Originally Posted by monotreme_man

der wille

how does one screw up a refractometer reading?

sometimes i find it hard to see the line, but simply redoing the procedure
normally makes it visible. when i started out, i would try taking five
readings in a row in order to check reproducibility but never found
skew readings. but your comment has made me worried; are there
failure modes i haven't anticpated?

If you don't check to make sure that is calibrated properly your readings will be off. Some calibrate with RO/DI, but I always use the calibration fluid, I want to make sure that it reads 35ppt accurately and could care less if it reads 00ppt accurately. I also take a sample from the display tank and one from the sump, for all my tests.

kimber45 · 12/01/2009, 09:07 AM

Quote:

Originally Posted by Madratter

I'm hoping (and think) you mean .0005. There is a vast difference between water at 1.023 and 1.028.

yep sry. not enough 0's. :P

Randy Holmes-Farley · 12/01/2009, 09:28 AM

I certainly would not say that one must have a refractometer, since there are other methods that are at least as good (conductivity, for example, or very high quality floating glass hydrometers), but refractometers are a fine way to go IF you calibrate them with a seawater standard, and not RO/DI.

You will likely get somewhat inaccurate readings if you calibrate with RO/DI and then try to use it in seawater.

der_wille_zur_macht · 12/01/2009, 10:04 AM

Quote:

Originally Posted by monotreme_man

der wille

how does one screw up a refractometer reading?

Lotsa ways. First and foremost, improper (or no) calibration - I'm fearful that many people see threads like this and think "oh, a refractometer will solve all my problems, because they're ALWAYS right!" then run out, buy one, and start using it, without even realizing they require calibration to a known standard.

But also poor handling/use of the instrument. If there are bubbles or dry spots on the prism, you'll get a blurry or poor reading. Or, if you're using an instrument without automatic temperature compensation, putting the sample on the prism and immediately taking a reading - if the sample and/or refractometer are at vastly different temperatures than the temperature your instrument is designed for, and/or the standard you calibrated to, you'll potentially be off. Letting the sample (or standard, when calibrating) sit for a few seconds to equalize to the instrument's temperature (which should be more or less room temperature, since most models without compensation are calibrated at 20 C) will remove this possible error.

Also, not properly cleaning the instrument can cause problems. I've seen people using refractometers that were practically crusted with the dried remains of prior samples. Clearly, that's going to cause issues.

Finally, these are delicate optical instruments - tossing them around, letting water get in the housing, etc - can all permanently damage them.

All that said, I would definitely agree that refractometers can be valuable instruments, and many people see them as easier to use than good hydrometers - but, it's important to understand proper use and handling, rather than just blindly believing the instrument will always be right, no matter what.

Jackie Blue · 12/02/2009, 05:32 PM

Funny thing I just ran across this problem today. Bout some new frags and noticed that they were not doing soo hot, along with my frogspawn, went in and had my water tested thinking that I wasn't doing something right and my ammonia might be sky high. Turns out it was my lame hydrometer. Tested my water with the stores refractor and my SG was 1.03+ and my hydrometer was reading 1.024. Bought a refractor and calabrated it, sure enough got the same reading as the store. Where I thought I was keeping my perameters in check I was really killing my tank. But hey all my other levels were good

. Don't screw around with those lame floating arm hydrometers, invest in a quality instrument.

11/30/2009, 04:48 PM	#1
Reverend Reefer Registered Member Join Date: Dec 2008 Location: Toronto, ON, Canada Posts: 883	the importance of a refractometer well, as some of you might know, i used to have a fish problem - i couldn't keep any fish alive. i tried everything under the sun and many thanks to everyone's suggestions. in the end, due to sheer luck, i solved the problem.... it was my specific gravity! i was using several different types of hydrometers: ones with moving arm bars, and one that floats and has a thermometer in it. these always gave me perfect readings. then one day, i bought a refractometer and that silly little thing that i didn't want to spend money on previously showed my SG to be over 1.032!!!! so i started adding more top-off water daily to dilute my water and now, im happy to say, i have fish!! i keep mostly LPS corals and i guess they were pretty tolerant of the salty water but i just wanted to post for my fellow newbies, GET A REFRACTOMETER! they are worth it.

11/30/2009, 05:06 PM	#5
C3gear Registered Member Join Date: May 2009 Location: Atlanta,GA Posts: 51	My refractometer was one of the best investments after my ro-di unit and skimmer. __________________ Men Do what they want Boys do what they can..... Current Tank Info: starting a new build soon

11/30/2009, 05:30 PM	#7
dwculp Registered Member Join Date: Dec 2003 Location: Carrollton, TX Posts: 2,338	Yep - I will NEVER be without a refractometer ever again. I had about 3 swing arm hydrometers and all three read different readings. I just took an average. Once I got the refractometer and calibrated it I was stunned at how far off the hydrometers were. I consider a good refractometer essential equipment. __________________ Remember, it will only get worse before it gets worse. Current Tank Info: 10 years - Currently have a 100 FOWLR

11/30/2009, 06:36 PM	#9
cloak Moved On Join Date: Jul 2000 Location: Stockton, CA Posts: 14,854	You can get around not having a refractometer is this hobby very easily. Just like you can not running any carbon or a refuge, using all tap water, incorperating bioballs, etc. It's not necessarily the equipment that's the problem, human error is a big factor. Aside from me breaking my $5.99 floating glass hydrometer sometiimes, replacing it with the same one has been working fine for almost 13 years. Last edited by cloak; 11/30/2009 at 06:45 PM.

11/30/2009, 06:41 PM	#10
der_wille_zur_macht Team RC Member Join Date: Sep 2003 Location: NY Posts: 17,749	IMHO the thread title should be "the importance of accurate salinity readings." Hydrometers get a bad rep on here, and while it's easy to get bad readings with one, it's almost as easy to get bad readings with a refractometer. Regardless of which tool you use, it's just a tool - it's not going to solve problems for you, or give you good results, unless you: a) know how to use it correctly, and b) know how to calibrate it, or at least check it for accuracy. In other words, I don't really think it matters which type of tool you use. Just pick a tool, then make sure you're using it correctly. Blindly assuming that a refractometer is "better" than any other type of measuring tool, and using one without calibrating or understanding proper procedure, is just as bad as using any other tool poorly. __________________ Inconveniencing marine life since 1992 "It is my personal belief that reef aquaria should be thriving communities of biodiversity, representative of their wild counterparts, and not merely collections of pretty specimens growing on tidy clean rock shelves covered in purple coralline algae." (Eric Borneman)

11/30/2009, 04:56 PM	#2
kimber45 Registered Member Join Date: Jan 2009 Location: michigan Posts: 455	not disagreeing with you but the funny thing is i have a 10+ year old hydrometer that to this day reads within .005 of my refractometer.

11/30/2009, 05:03 PM	#3
Madratter Registered Member Join Date: Aug 2009 Posts: 223	Well I could name names but I bought I so called calibrated Hydrometer that was no where close to the refractometer. My refractometer was reading .003 higher. And getting all the air bubbles off to get a "accurate" reading with the hydrometer was a royal pain. I have spent "some" money in this hobby I wish I had back, but a refractometer was money very well spent.

11/30/2009, 05:21 PM	#6
RussR19146 Registered Member Join Date: Apr 2009 Location: Philadelphia, PA Posts: 104	Just bought a refractometer myself and while the numbers seem close to the swing arm hydrometer the peace of mind is well worth it my best purchases so far - temperature controller, refractometer and phosphate removal system (after the fish and coral of course)

11/30/2009, 06:41 PM	#11
spleify Registered Member Join Date: Dec 2003 Location: Denver, Colorado Posts: 9,579	IMO a refractometer is a must. I will never be without one either __________________ Make it a Great Day!!!! Current Tank Info: 60 gal SPS cube, with 25 gal refugium, 400W MH, DIY Lumenarc III, DIY skimmer, DIY stand and canopy. 40 breeder LPS with 40 gallon sump, DIY stand, 250W MH

11/30/2009, 06:46 PM	#12
Big Country_IL Registered Member Join Date: Feb 2009 Location: Rock Island County, Illinois Posts: 54	I switched to a refractometer after about 6 months and wish I would have earlier. Just added a temp controller now and also wish I would've started with it. Hydrometers do work, but I prefer the refractometer.

11/30/2009, 07:02 PM	#13
floridazooguy Registered Member Join Date: Sep 2008 Location: Florida Posts: 118	I agree both work but I also use both to check so im sure.

11/30/2009, 07:13 PM	#14
Jtro Registered Member Join Date: Jun 2007 Location: VA Posts: 79	My refractometer was slightly off purchased some calibration solution and its good as new not sure if it was off since it was new or the kids may have adjusted for me.Will keep a eye on it.

11/30/2009, 07:20 PM	#15
Juruense Registered Member Join Date: Nov 2008 Location: Fort Wayne, IN Posts: 1,138	I use a floating glass tube hydrometer, it is a little off but I know that because I had it calibrated to a known good refractometer at the LFS to see exactly how much it was off. It reads a little low but I know that so it is ok I would prefer to have a super accurate measuring device however.

11/30/2009, 08:04 PM	#16
sam11909 Maxi Mini Join Date: Jun 2009 Location: Tallahassee, FL Posts: 1,039	Same thing happened to me, didn't know why everything kept dieing for no reason. __________________ Samuel A reef aquarium is simply an aquarist's best try of painting a small section of the ocean and containing it in a glass frame. Each new coral adds a new color or brush stroke to the painter's toolbox. Current Tank Info: The Stair-Stepping Nano System

11/30/2009, 09:34 PM	#17
joel g Registered Member Join Date: Feb 2007 Location: southern ma Posts: 68	I have been trying to buy one for a while but every time I go to buy one I end up bringing home a couple of frags instead

12/01/2009, 04:53 AM	#18
monotreme_man Registered Member Join Date: Aug 2008 Location: Southern California Posts: 228	worried? der wille how does one screw up a refractometer reading? sometimes i find it hard to see the line, but simply redoing the procedure normally makes it visible. when i started out, i would try taking five readings in a row in order to check reproducibility but never found skew readings. but your comment has made me worried; are there failure modes i haven't anticpated?

12/01/2009, 09:28 AM	#22
Randy Holmes-Farley Reef Chemist Join Date: Apr 2001 Location: Arlington, Massachusetts Posts: 86,233	I certainly would not say that one must have a refractometer, since there are other methods that are at least as good (conductivity, for example, or very high quality floating glass hydrometers), but refractometers are a fine way to go IF you calibrate them with a seawater standard, and not RO/DI. You will likely get somewhat inaccurate readings if you calibrate with RO/DI and then try to use it in seawater. __________________ Randy Holmes-Farley Current Tank Info: 120 mixed reef

12/02/2009, 05:32 PM	#24
Jackie Blue Registered Member Join Date: Feb 2009 Location: Elgin, IL Posts: 333	Funny thing I just ran across this problem today. Bout some new frags and noticed that they were not doing soo hot, along with my frogspawn, went in and had my water tested thinking that I wasn't doing something right and my ammonia might be sky high. Turns out it was my lame hydrometer. Tested my water with the stores refractor and my SG was 1.03+ and my hydrometer was reading 1.024. Bought a refractor and calabrated it, sure enough got the same reading as the store. Where I thought I was keeping my perameters in check I was really killing my tank. But hey all my other levels were good . Don't screw around with those lame floating arm hydrometers, invest in a quality instrument. __________________ How am I doing? Well I got ten fingers and toes. Current Tank Info: 120 Gallon. Custom made refugium sump 30 gallons.