How accurate is this hydrometer?

[DBlackman]

Hey Guys,

I have been using, 'Coralife Deep Six Hydrometer' for SG level testing.

I while back, I heard that the a certain hydrometer model is off by 0.04, so I have been staying within 1.021 and 1.022, with the Coralife model.... BUT, now I am confused and need clarification. I am concerned that I have been keeping my SG levels too low!

For Reefers that are using the 'Coralife Deep Six Hydrometer', please confirm what SG levels you are using?

[Bill S]

My personal opinion: If a product has the word: "Coralife" on it, it probably is junk...

This is a "swing arm" hydrometer. These type of hydrometers have likely killed more sw fish than any other single piece of equipment. They generally aren't that accurate to start with, and over time they get worse - MUCH worse.

Buy a floating hydrometer.

[BigKGlen]

Derrick,
I'd consider writing off the hydrometer as a loss, and get you one of these. (http://www.marinedepot.com/ps_AquariumPage~PageAlias~thermometers_refractomet ers_hydrometers_captive_purity_refractometer.html) MUCH MORE accurate and reliable.

[ErikH]

I had a hydrometer.... NEVER AGAIN! My salinity was off by something like .9.... Instade of bein at .23 it was at .32

[Bill S]

Erik, not ALL hydrometers are bad - I can pretty much say all "swing arm" hydrometers have the potential to give inaccurate readings. A decent "bobber" is always accurate if you keep it clean and if it was accurate to start with. Here's a really GOOD hydrometer:

http://www.tropic-marin.com/web/english/produkte/araeo.htm

[FSU]

Yes, I have also crashed an entire tank when I first started into the salt water hobby due to hydrometers! Pay the extra money and get a refractometer. One of the better investments in the saltwater hobby IMO!

[envy]

only bad thing about the floting type is if you drop it then it can become inacurate or break but your refractometer is a better buy

[ErikH]

Yes, Bill, thanks for correcting me! :p

[DrMark]

This is an expensive hobby, no doubt. Some items can be bought it in good used condition to help defray costs (people are continually upgrading, downgrading, etc.). Some areas should not be sacrificed. A basic refractometer can be bought for around $50. Is saving $40 with a cheap swing arm hydrometer worth the risk of hundreds (more commonly thousands of $ of coral and fish). I have the same answer for tap vs. RO/DI, etc. If I am going to take on the responsiblity of owning and raising a living animal, I feel it is my duty to provide the very best circumstances for that animal to thrive in (it is more than just $$ at stake, much more).
That being said, a refractometer that can be calibrated with DI water is simply a must. Calibration should be routinely checked on these.
Mark

[cpreefguy]

Erik, not ALL hydrometers are bad - I can pretty much say all "swing arm" hydrometers have the potential to give inaccurate readings. A decent "bobber" is always accurate if you keep it clean and if it was accurate to start with. Here's a really GOOD hydrometer:

http://www.tropic-marin.com/web/english/produkte/araeo.htm

Wow, it has a max standard deviation of +/- 0.0005
I may have to pick one of these up and test it against my refractometer...

[DBlackman]

Thank Guys... I will be looking out for a new/used 'Refractometer' !!!

[DrMark]

Wow, it has a max standard deviation of +/- 0.0005
I may have to pick one of these up and test it against my refractometer...

I do like gadgets and toys and may also get one of these too. Germans make good stuff......

[RayAllen]

I need to get my self a refractometer.

[BioCube14]

i had a tank crash due to salinity..go with a refractometer..ebay has them for like $20 or you can buy the same one from marine depot for $45 i think

[ErikH]

Refractometers make people look super scientific. When I first started the hobby, I saw alot of people using them in stores. I thought to myself, "Dang, that guy is a nerd."
Now everytime I use one, I get to laugh at my own stupidity, which, I might add, I do FREQUENTLY... :)

[hobogato]

i lost a bunch of corals die bc of sg issues using a refractometer. make sure you calibrate it frequently or you could be just as bad off as using a swing arm.



i had a tank crash due to salinity..go with a refractometer..ebay has them for like $20 or you can buy the same one from marine depot for $45 i think

[Bill S]

Here we go again:

The problem with refractometers is calibration:

1) you actually HAVE to do this. Some very good reefers have crashed some very nice tanks buy being inadvertantly lazy. It's just way too easy to do.

2) the RIGHT way to calibrate a refractometer is to use distilled water AND calibration fluid. If you only use distilled water, you really aren't doing it "right". The calibration fluid has a salinity above seawater. So, you calibrate above and below seawater salinity. Just about NO ONE does this - and you should. Obviously, your other choice in calibration is to use a good hydrometer]

BTW, I keep 2 hydrometers. A few years ago, I hadn't broken one in 30 years, and then I managed to break 2 in the same day!

[RayAllen]

Ace do you also use a floating hydrometer? I have to be honest and say I probably wouldnt calibrate a refract as much as I should so I may go with the floating Hydrometer as bstreep recommended.

[hobogato]

i do now :)

[DBlackman]

Okay... Tropic Marin Hydrometer... it will be.

[ErikH]

The floaters are wise to own :) I have mine calibrated the right way as Bill speaks of, and every time I get someone's water I test it to see what their salinity is at. I usually send them a pm and share what I found on mine. It's wise to trade water with someone else at a meeting so they can test it later and see if everything is inline.

[RayAllen]

Im on board with you Dblackman

[thesponge]

I brew my own beer and use a floating hydrometer often in that hobby. One thing to make sure of with a floating hydrometer is that there are no air bubbles around it or under it (it happens in brewing sometimes) and that it's very clean! Analog is sometimes better.

[alton]

Buy the large Hydrometer, do not buy the small ones that most fish stores sell they are junk! Oh yea in 18 years I have broke two.

[aquasport24]

So, how do i get a hold of the floating hydrometer? Is there a local place or where excatly online do i get it?...thx..i want to give it a shot.

[thesponge]

Austin Home Brew sells them in the Austin area. But as I am typing this I see you are in San Antonio so....

[ErikH]

They sell the floaters for around ten bucks at about every LFS in SA.

[aquasport24]

thanks

[Bill S]

Be careful... Some of the "floaters" are better/more accurate than others. When you buy one, have it checked at the store.

[tony]

This is an expensive hobby, no doubt. Some items can be bought it in good used condition to help defray costs (people are continually upgrading, downgrading, etc.). Some areas should not be sacrificed. A basic refractometer can be bought for around $50. Is saving $40 with a cheap swing arm hydrometer worth the risk of hundreds (more commonly thousands of $ of coral and fish). I have the same answer for tap vs. RO/DI, etc. If I am going to take on the responsiblity of owning and raising a living animal, I feel it is my duty to provide the very best circumstances for that animal to thrive in (it is more than just $$ at stake, much more).
That being said, a refractometer that can be calibrated with DI water is simply a must. Calibration should be routinely checked on these.
Mark


GREAT POST!!!

[DBlackman]

Did a google search and found the following sites:
http://www.aquatichouse.com/Test%20Kits_files/hydrometer.asp
http://www.aquabuys.com/page/aqb/PROD/tms_hydrometer

This is a 'Good Read':
http://reefkeeping.com/issues/2004-07/rhf/index.php

[Paul28]

I run this one ive had no problems tanks looks good all per perfect knock on wood :bigsmile:http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=9957

[DBlackman]

I went over to 'Addboys' place with a sample of tank water and the 'Coralife Deep Six-hydormeter' to test comparisons with his afractometer.

His tank water:
Refractometer registered: 1.0255

My water sample:
Coralife Deep Six registered: 1.0215
Refractometer registered: 1.0265

Go figure.... frown

[Bill S]

Ouch...

And people wonder why I rail on swing arms!