hyrdrometer

[dakotahoku]

I am trying to measure the sg of my tank. I have two types of hydrometer's, the glass floating and the swing arm. I get two different readings, the sg measurement with the glass floating is lower (about .004)
than the swing arm. Why is that? Which one should I follow?

 

[Electrobes]

I think the glass floating one is more accurate.. but I wouldn't exactly quote me on this... whats your SG? and what type of tank do you have?

 

[dakotahoku]

I have a 55g FO tank and my fish has come down with ick, so I am trying to do the hyposalinity treatment. What would be the lowest SG/salinity that I can go without harming the fish? I read the post on hyposalinity treatment and I am trying to get my tank to 1.009 SG.

 

[reefrunner69]

How long is the glass floating hydrometer, if it is not a minimum of 12 inches, I would trust the swing arm over the floater. Is there someone in your area or at the LFS that might verify your readings with a refractometer?

 

[phases99]

Did you ever find out which one was accurate? I bought a Seatest hydrometer today and it is reading .005 higher than my 12" Hagen Living Sea floating hydrometer. It had me concerned enough to make up a batch of IO salt adding 8oz of salt to 2 gallons of water. My floater read 1.022 and the Seatest read 1.027. I think I'm going trust the floater, but I'll probably buy me a refractometer so I sleep better at night.

 

[Aqua-Zodica]

Get a refractometer. Its the only way to get truly correct SG readings, otherwise get a lab grade hydrometer.

 

[24 hours? NE!]

Check out this thread. I ended up getting one, but I haven't used it yet. Sounds like if you're looking for a specific reading and it's for the health of your fish, you should probably be as accurate as you can.

http://www.aquariumadvice.com/viewtopic.php?t=24722&highlight=

 

[MYTY1705]

Make sure the temperature is correct for the floating hydrometer. They are calabrated for temperature and it will change your readings.

 

[phases99]

I brought both my hydometers to a LFS and tested them against his water. It turns out the Instant Ocean plastic hydrometer was almost identical to his refractometer at 1.024. My Living Sea 12" glass floater read low at around 1.020. I'm glad I found this out before adding any life to my tank. This is the second Living Sea Hydrometer I've used and they both read the same. It says it is calibrated for 77f and my water is about 78f. If you are using one of these as your primary device beware!