View Full Version : Refractometer or not???
GSXRnutter
04-03-08, 01:08
How do you measeure yours???? SG/salinity that is, do you use the swing arm type led to believe holy inacurate, or have you shed the pounds!!(£££) and opted for the refroctometer type, either way, what are the results, especially swapping from one to the other??
edited the poll to include other options that people may use. :)
Have voted refractometer, i am fed up with buying new floating hydrometers. I break them more often than use them now.
Taste! What a good Idea means I can combine siphoning with a useful judge of SG. Good Thinking!!:cool:
proplus888
04-03-08, 02:00
I gave up after using 30mins of the Red Sea swing arm......not once did it give me the same reading in 30mins!!! Ran out and got a D&D refract instead.
As a recent newbie(2 months),the first bit of advice I got on here was to get a refractometer.Got it from Bluzoo. JOB DONE.
I use a refractometer as the swing arms are so inaccurate that you never know if the reading is correct but i have also just ordered a conductivity probe for my aquatronica so i will hopefully have a belt and braces setup.
:)
I got a refractometer from China for £20 so can't argue its too expensive really.
we had a floating type one when we first setup, got some advice and the thing never made it out the box.
Floating one for me but I will be getting a refractometer.
instantsquid
04-03-08, 09:44
Lab grade density hydrometer for me. Not the easiest thing to use, but I know it's accurate. :)
I have a swing arm and an Aqua Medic Marin Control Digital.
The Aqua Medic needs calibrating every week and the swing arm is always spot on.
Very strange :(
had a swing arm when i first started, then when a new toadstool i bought died and everything else was perfect, i bought a refractometer!!! my swing arm said 1.026 my refractometer said 1.042!:annoyed: nice hey!!!!
Used to have a floating hydrometer, never really trusted it, now have a refractometer :thumbsup:
Had a "high precision" hydrometer for years (and trusted it). A year or so ago, when I returned a firefish to an LFS the owner tested the water with a refractometer and I found I'd been running at around 1.029 :rolleyes: rather than the 1.026 I thought it was!
I now use a refractometer.
John
instantsquid
04-03-08, 12:32
John,
With my Brannan hydrometer - at 25 degrees, a salinity of 35 ppt measures a density of 1.023. A reading of 1.026 (at 25 degrees) is a salinity of 39 ppt. Would that account for your discrepency?
new mariner
04-03-08, 12:37
I have voted refractometer, still using swing arm at the moment, but refractometer is to be purchased very soon
I use a refractometer as the swing arms are so inaccurate that you never know if the reading is correct.
:)
Same as LB for me:D
always used a floating hyd before, but found it was too rubbish and inaccurate for what I wanted, so got a deltec refractometer
Used to use a cheapo swing arm, which I never trusted. Then the floaty bit fell off (the white disc on the arm), and I stuck it back in the hole with a pen and a lot of patience, so I thought it must be really knackered.
Bought a refractometer and discovered my battered old swing arm was spot on all along. Oh well!
jamie reefer
04-03-08, 17:23
Hi all
Refractometer for me would'nt be without mine....
Cheers Jamie
John,
With my Brannan hydrometer - at 25 degrees, a salinity of 35 ppt measures a density of 1.023. A reading of 1.026 (at 25 degrees) is a salinity of 39 ppt. Would that account for your discrepency?
Remember that there are two scales for S.G. depending on what the reference temperature is, that is responsible for no end of confusion.
I use a good quality floating hydrometer, that way I know that nothing can go wrong with it - unless it decides to change volume or lose mass. Never needs calibrating = stability.
Doesn't have the same nautical feel as one of thoses telescopes... I mean refractometers... LAND AHOY!
Cheers,
Martin
I treated myself to a refractometer last xmas. I had been using a swing arm and thought i was running at 1024 salt. When i used the refractometer it told me i was actually running at 1030 ! They are a must have piece of kit .
Marineboy1010
04-03-08, 19:43
Refractometer for me, I was lucky enough to get the advice to get one of these before I set up and glad I did !!
I use a refractometer, but any decent hydrometer will be just as good. The most important thing is knowing how to use your tool. The refractometers that hobbiests can afford at <£50 tend not to be very accurate throughout the whole scale. If you calibrate them at 0 with RO water you can end up inaccurate at sea water.
The end result is to make sure that you calibrate your cheap refractometer with a known salinity solution closer to SW then pure water.
At our price points most floating hydrometers will be as accurate as refractometers.
bristol_rich
04-03-08, 19:59
Refract for me, the most accurate way i have found:)
Defintely refract for me. Had one of the old swing arms, compared this with refrac and it was some 0.02 off in terms of accuracy!
neilharris
05-03-08, 20:03
I use a refractometer, checked against a floating hydrometer every few months. THat is for the water changes.
Tank is monitored 24/7 by IKS conductivity probe.
i use the refractometer as i was told it was more accurate and because i ci=ould not the bothered to do a lap of the house to clean my swing arm one in fresh water.:laugh::laugh:
refrac for me results were more accurate and gave me an excuse to spend more money :p
eddiedundee
05-03-08, 21:34
refractometer dd best for me
I always use a refractometer or a digital salinity meter. IMO SG is outdated and outmoded, working with litres and ppt is SO much easier.
35ppt = 35grams/litre
Campbell
come on!!!!...no one else does the taste test??
Ah yes - but who calibrates their Refractometer correctly? Useful link http://reefkeeping.com/issues/2006-12/rhf/index.php
Quigs - I recently calibrated my refractometer against a calibration solution rather than RO/DI water. So much for the instructions that were provided by the manufacturer! It turns out that I had been running my reef at 1.022 for over a year. I now use a properly calibrated refractometer but refuse to let go of the swing arm and floating hydrometers I purchased over the years. The latter are used for water changes as a fail safe. BTW, the swing arm reads a little low but the floating hydrometer is right on but hard to read.
The above two posts illustrate my point. Many people claim their refractometer is more accurate, but how many people have truly calibrated and/or tested their refractometer against a known salinity?
had the floating one, i dint find it to bad. now i have a refractometer best thing out. never go back.
iv had the swing arm type utter crap IMHO but got the cheapo 3quid floating stick seems to be doing the job fine
When I was in the UK I used a large scaled floating hydrometer calibrated by the national physics laboratory, quite expensive but very accurate, had it re-calibrated evey year.
Here I only have a swing arm and a poxy little hydrometer and am looking for a refractometer, I Googled refractometer on Google Indonesia and so far am only getting results for digital refractometers anyone used them?
Maybe I'll end up using a SG bottle and balance for calibration.
i voted for probe but thinking of it should be other.
imo you cant trust any of these methods log term all of them drift and need calibrating.
refractometer will be my choice when i'm up and running again. The write ups are good, and it's a nice looking toy, i get to play mad scientist muhaha.
Daveyboy34
19-03-08, 13:46
Voted Refractometer
Bought a Refractometer from a Chinese Lab on line
Just upgraded tank and it came with a D&D Refractometer so now have a spare
Will check readings against each other out of curiosity tho'
Dave
freewilly58
21-03-08, 18:27
refractometer for me
ive got a fractometer but find it hard to read. swing arm is much easier
refractometer all the way accurate and easy to use
ive got a fractometer but find it hard to read. swing arm is much easier
Sorry how can it be hard to read, put water on plate look through eye glass and get reading, unless of course your eye sight is not very good in the first place of course.
Swing arms are known for being very unreliable in getting an accurate reading due to what has been mentioned before things like air bubbles that will make a difference to the reading.
:)
use both conductivity probe & refracometer.:D
Refractometer - definitely.:thumbsup: Had swing arm when first starting out, but found it was going between extremes and concerned when doing water changes and getting right salinity.
ive got a fractometer but find it hard to read. swing arm is much easier
Do you wear glasses? I have to take my glasses off to read my refractometer. With them on I can't get my eye close enough to the eyepiece.
scaredboy1
04-06-08, 16:58
Refractometer is what i find easiest and most reliable. Although i wear glasses and they are a pain:mad:
jut
pete smith
04-06-08, 17:02
Refractometer for me its so simple and thats how I like it.
Regards
Pete :thumbsup:
Refractometer, wouldn't use anything else now, if only all test kits were this easy.
Refractometer, the only way to go. Although the glasses thing is a pain
refractometer as it seems does every else, nearly
Had a hydrometer before and up untill tank crash, but now i have refractometer.
Trying to avoid another mishap, i've been told they are a lot more accurate:thumbsup:
jaseribbit
01-10-09, 12:49
I use a refractometer as the swing arms are so inaccurate that you never know if the reading is correct all you need is an air bubble on the needle and the reading is wrong
Is the need for such accuracy necessary? Seeing as most people keep systems at differents SGs ie in the range of 1.024 - 1.026, does it matter if the swing arm isn't accurate provided you always mix to the same reading ( and at the same temp).
I've used the same Seatest swing arm since 1991
i use a hydrometer as i find this easier even thu i have a d&d refractometer :D
got to be a refractometer
refractometer with temp compensation
aragonite55
04-09-10, 15:15
Using my third floating hydrometer, when I bust this one it will then be a refractometer.
I use a refractometer hoping to get the new D&D one.
dvearncombe
15-11-11, 16:39
I used a swing arm for years, happy in the believe that I was spot on a nice stable 1.024.
When I eventually bought a refractometer, I found out that I was actually at 1.030.
2 lessons learnt there:
1. always cross check your readings/calibrations with other kit (LFS's should do this for you, if you ask nicely).
2. Buy a refractometer from day one. Sal is key parameter for marine and the cost of refrac. is tiny % of your overall investment (kit + livestock).
d&d short scale read refractometer the best and would not be without it.
JamieLloyd
15-11-11, 21:05
i had a swing arm for ages.. decided to get refractometer and the reading are exactly the same with both.. i usually just use the swing arm now as its easier
matt_storey
18-11-11, 18:48
i use a refractometer
Always a refrac, easy and accurate
I used a swing arm for years, happy in the believe that I was spot on a nice stable 1.024.
When I eventually bought a refractometer, I found out that I was actually at 1.030.
2 lessons learnt there:
1. always cross check your readings/calibrations with other kit (LFS's should do this for you, if you ask nicely).
2. Buy a refractometer from day one. Sal is key parameter for marine and the cost of refrac. is tiny % of your overall investment (kit + livestock).
as above. not for years but chased levels for about 6 month until i got a proper refractometer
Definately recommend a refractometer, such an easy bit of kit to use!!
A refractometer was one of my first purchases as test kits came with my first setup, i wouldn't swap it as its so easy to use.
Thanks Brian
I got a TMC refractometer off the classifieds on UR - mint condition for £15
Ditched the swing ar hydrometer as it didin't give the same reading twice!
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