Hydrometer accuracy
Printed From: Utah Reefs
Category: Specialized Discussion
Forum Name: Reef Chemistry
Forum Description: A place to discuss reef chemistry.
URL: http://www.utahreefs.com/forum/forum_posts.asp?TID=50291
Printed Date: September 23 2025 at 2:32am
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com
Topic: Hydrometer accuracy
Posted By: BillyC
Subject: Hydrometer accuracy
Date Posted: July 20 2011 at 1:01pm
|
I've been reading the reviews on my hydrometer (coralife deep six) and the more I read, the more I hear about how horribly inaccurate hydrometers are. Is buying a refractometer really necessary?I've been using my hydrometer ever since I got my 55g. All of the params have been great but I'm starting to wonder if my specific gravity really is what it reads. Does anyone know more about this?
S.g. 1.024 Alk. 9.6 dKH Cal 440 ppm pH 8.2 |
Replies:
Posted By: xlr8r
Date Posted: July 20 2011 at 1:09pm
|
Find someone who has a refractometer and have them check your water. Then compare that to your hydrometer reading and note any differance. Then you'll know how much to adjust for your hydrometer. Then be sure to wash out your hydrometer with freshwater after each use. An occasional vinegar bath is ok to. This will keep it consistant.
my $.02  ------------- When you hear hoofbeats....Think of a zebra |
Posted By: TriggerHappy
Date Posted: July 20 2011 at 1:28pm
|
^^^ Ditto ------------- 210 gallon Mixed Reef |
Posted By: Josh95
Date Posted: July 20 2011 at 2:21pm
| as long as its consistent you should be fine, check it with a refractometer and just account for the difference |
Posted By: Tanuki
Date Posted: July 20 2011 at 3:07pm
|
I checked mine against a refractometer and it read the same. I think it is funny how much you read online about them being terrible, and yet every LFS sells them. If they were that bad, no one would buy them, and they would stop making them. ------------- Defending Reefscape Champion (I Think) |
Posted By: TriggerHappy
Date Posted: July 20 2011 at 3:21pm
Not true, I had one that was off. It was reading 1.026 and I kept killing newly added fire shrimp. Checked it against a refractometer and I was really at 1.031. So, cross checking every so often is a good thing.  ------------- 210 gallon Mixed Reef |
Tanuki wrote:Posted By: BillyC
Date Posted: July 20 2011 at 3:44pm
| Good to know I'll do that. Just gotta find someone that has one now. |
Posted By: Ryan Thompson
Date Posted: July 20 2011 at 7:32pm
I am sorry but this simply isn't true! A LFS is out to make money to stay in business, it is that simple. They will sell you anything to make a dollar whether you need it or not. That is business and selling 101. The LFS' are not evil or anything but they need to keep the lights on, they need money. It is up to us consumers to do our RESEARCH before buying. I am sorry but I won't trust any salesman, ever. I have been in sales for a long time and I know how they work. Do your research and find out from USERS what really works and what doesn't. A hydrometer will work but you need to calibrate every 6 months or so IMO. I had a hydrometer reading 1.022 and the water was really 1.032! I even cleaned it out after every use and it still was off in the end. |
Posted By: Tanuki
Date Posted: July 21 2011 at 9:31am
|
I did not ever say that all hydrometers are perfect, I said mine has been pretty accurate. If they were a complete joke and waste of money, than the LFS would sell the Refractometer only. I mean initial set up is when people spend the most on the tank anyway. What is another 50-100 $ if it will keep your salinity dead on? If the Hydrometer did not work at all, no one would sell them. It makes you look bad as a business and you lose credibility. Selling garbage is not how you stay in business. ------------- Defending Reefscape Champion (I Think) |
Posted By: djutah
Date Posted: July 21 2011 at 6:09pm
|
not sure how accurate this method is, but the salt i use measures 1/2 cup per gallon of water when mixing, so i guess the salinity from the mixture will hopefully be between 1.021 and 1.024. i will from time to time test my hydrometer against 1 gallon of mixed salt water and see if it stays in this range. this method is probably not even close to as accurate as testing against a refractometer though. |
Posted By: Ryan Thompson
Date Posted: July 21 2011 at 6:19pm
I wouldn't ever recommend doing this because salt mixes vary. You could get one batch where it reads 1.018 and the next will read higher. I have had some salts where it took over 3/4 cup to get my salt to the 1.025 range. Hydrometers work fine, you just need to clean and calibrate them a lot. edit - fixed some terrible typos, lol |
Posted By: Tanuki
Date Posted: July 22 2011 at 9:34am
|
^Agreed. I never trust the measuring guide on my salt.
------------- Defending Reefscape Champion (I Think) |
Posted By: BillyC
Date Posted: July 22 2011 at 9:58am
| I ended up comparing my hydrometer with a correctly calibrated one. Turns out that to read mine I have to add 0.002 to what it reads. Luckily I kept my salt at "1.024" so the actual specific gravity was at 1.026 which is not bad. I'd definitely recommend everyone get their's checked out. |
Posted By: djutah
Date Posted: July 22 2011 at 10:15am
| good to know, i prob need to get my water checked and verify the numbers also. |