The Importance of a Refractometer

[terry4505]

I have had my 120 reef up and running for about a month. Prior to that, all the inhabitants of the 120 were in my 75g for about 6 months. Prior to that, the 75 was FOWLR for almost 10 years.

During those 10 years, I have always used swing arm hydrometers to measure specific gravity. I have two of different brands that have always agreed with each other, so I assumed they had to be close.

Recently, I became confused about my chemistry (Calcium was up over 540 per API test) and decided to take a sample to the LFS so I could figure out what was up.

Turns out that my water was able to hold so much calcium in suspension because my specific gravity, which I thought was about 1.025-1.025 was actually hovering around 1.028-1.029.

I obviously left the LFS with a newly purchased Refracto in tow. My fish and corals had shown no ill effects of the increased salinity, but I know this was well high of where it should be. I am bringing it down slowly over the course of a few days.

I was wondering why it seemed to take so much salt mix to reach what I thouhgt was the proper specific grav.

The reality is, there are some things you just have to have (RO/DI filter, skimmer, good lights, refractometer). Lesson learned.

 

[EllieSuz]

You should post this in the "New to the Hobby" thread. Good advice for beginners.

 

[cjrudy]

What brand do you have now

 

[Tonynlo]

I use to use reef crystals and mix in a 5 gallon bucket. Using a hydrometer, it generally read 1.025 regardless of the true SG. My refractometer would read a lot lower. Im unsure if my 5 gallon bucket held more than 5 gallons or if the recommended mixture was off. I have changed my mixing procedure to just mixing salt in a brute container and adding more salt until my salinity is perfect. I no longer measure the amount of water, it's the salt mix that is cautiously added.

 

[alanbates12]

IMO the swing arm refractometers are asking for trouble. I too had the same trouble but it was causing other problems, ie: cyanobacteria, corals not good and aided in the death of an anemone. So after some research I purchased a Milwaukee Instruments Seawater (Salinity) Refractometer. Very easy to calibrate and easy to use. http://www.amazon.com/Milwaukee-Instruments-Seawater-Salinity-Refractometer/dp/B00316KF5U

 

[terry4505]

Not sure what the brand is (ATC or something like that). It is very easy to use/read... My three year old daughter thinks it is like magic looking into it.

On a side note, getting her interested in the tank (feeding, water changes, testing) has been one of the most rewarding parts of owning the tank. She helps me with food prep, etc. Instead of my tank being something that takes me away from her, it has become something we do together.

 

[block head]

just make sure and calibrate your refractometer often. the same thing can easily happen with the best refractometers.

 

[alanbates12]

+1 Block head

 

[sf_ramsden]

just make sure and calibrate your refractometer often. the same thing can easily happen with the best refractometers.

This is most important when using a refractometer. Just because a LFS is using one, or you own one doesn't mean its 100% correct. These still need to be calibrated on a regular basis. I finally got calibration solution for mine after 1+ yr of use and mine was off by a huge margin!

 

[terry4505]

Already have calibration solution and will use it regularly

 

[mr.maroonsalty]

There is nothing wrong with hydrometers if you calibrate them; a lot of very good reef keepers use them, but they also know where it should read 1.026. If you're not calibrating your refractometer every time you use it you'll have troubles because instead of being consistently off like a hydrometer, a refractometer will wonder all over the place.

 

[IronMan72]

While were on the topic, here's a great article related to making salinity measurements with a refractometer.

http://reefkeeping.com/issues/2006-12/rhf/index.php

 

[alanbates12]

That's the great thing about the Milwaukee, you can callibrat it with RO/DI water. Very easy to use. This is the factory recommendation. Also I know the exact measurement when making my salt so I use that as a backup check. So far I'm very happy with it.

 

[block head]

That's the great thing about the Milwaukee, you can callibrat it with RO/DI water. Very easy to use. This is the factory recommendation. Also I know the exact measurement when making my salt so I use that as a backup check. So far I'm very happy with it.

milwaukee makes fine products. rodi is not an accurate callibration solution. the laws of physics apply, despite what the mfg might claim.

 

[votek]

This is something I will be investing in, in addition to the neptune apex.