Hydrometer ???

[dbmet]

Since I'm buying test kits..I might as well get the hydrometer.

Which hydrometer do you use, or do you use a salinity Refractometer?

thanks for the help..
daryl

[ 08-19-2001: Message edited by: dbmet ]

[nobby]

hi there dbmet
im using the deep 6 hydrometer at the moment and im quite pleased with it.
im sure there is better out there but if it does the job im happy to spend the extra on corals.

[Drew]

I think I use a deep-six too. It was $12. Hydrometers are notorious for giving bad readings, if you have extra money I would spring for a refractometer. I however don't have extra money and will stick with my deep six, it will get the job done, just not a precise

Drew

[Brooke]

We just got a refractometer from someone leaving the hobby. It is very cool. Very precise. Easy to calibrate. It was .002 different than our deep six. IOW our deep six we were at 1.025, when we were really 1.028. That's a bit high! Very cool thing to splurge on!

Brooke

[Blake]

This is what I do:
1. Get a glass
2. Put some of the salt water into the glass
3. Take a big gulp
4. Cough
5. Take a guess as to the salt content

[FishDaddy]

Refractometers are the most accurate and consistent, but they run about $75-100, depending on wherer you buy them.
I use a Tropic Marin floating glass hydrometer. It's quite accurate for about $20. I also have an Aquarium Systems SeaTest plastic swing-arm box that I use for rough work. It generally reads about .001+ lower than the TM. It is important to get all the air bubbles off the plastic swing arms or you will get an abnormally high reading with just a small bubble.
Here is a good article that discusses the plastic hydrometers. http://www.harboraquatics.com/hydrotest.html
Dick

[Drew]

To elaborate on what Dick said, tiny bubbles can cause inaccuracies either way depending on which side of the arm the bubble is on.

Drew

[tdwyatt]

If you are really concerned about using a swing arm hydrometer, you can test the zero point by using a known high quality distilled water sample to test the 0.000 reading. Distilled water at 76 F will read at 0.0000 for those hydrometers calibrated at this temp. If it is off a little, they are generally off by that much throughout the scale as well, and you can correct the readings by knowing what the error amount is from the amount above or below 0.000 for the distilled water reading. The deal is not that the water is at exactly 35 ppt, but that it is CONSISTANT at the level that you do choose. I do recommend as close a salinity to natural seawater as possible (35 to 37 ppt depending on your biotope that you are mimicing) and most swing arm hydrometers will measure this closely enough for marine aquaria use, but the refractometers are both much more accurate and precise and are really kewl to use!!!

[Rick O]

Hi Fishdaddy,

I have a question about the Tropic Marin hydrometer. The label on the container says that the blue area is from 1.020 to 1.023. It looks to me like the blue scale goes from 1.0205 to 1.0235. In the pic is the pencil pointing to 1.023 or 1.0225?

Thanks,
Rick

[FishDaddy]

Hey Rick,
Sure looks like 1.023 to me! Mine has the same label. Another label, "Directions For Use", says "Read figure touched by water surface line."
These things are "Handmade in Germany"; maybe they lost something in the translation?
Dick