Hydrometer question

[Blakskall]

Ok so ive been acquiring saltwater equipment for the last 6 months and i finally have everything to start mine, im in the stage of mixing saltwater, im doing the first batch in my aqaurium with a powerhead and a heater, i made sure the water was as warm as what my tank would be, 75 degrees. I'm using RO water as well. Well i started mixing putting in a fairly good amount of salt mix, i dipped my hydrometer and it gave me a low result, and then i dipped it again just to be sure and it gave me a pretty high result, it there something wrong with my hydrometer? its an instant ocean swing type model

thanks

 

[Tomchong22]

You have to season the hydrometer. Ie let it sit in saltwater for 24 hours. U should have saved up for a refractomitor.also never mix saltwater in the tank. Always in a bucket

 

[Maya]

Air bubbles can skew the results as well. Hydrometers are hit and miss. Some are pretty accurate and some are so far off the mark it's not even funny. Once you figure out how to consistently use it, you should have the LFS check your salinity and compare it to your hydrometer.
Also, make sure that you are checking the salinity after the salt has time to mix. It doesn't dissolve instantly. It needs time to create the necessary chemical reactions.

 

[Maya]

Sorry for the double post but ..the Husband wants me to add that you also need to set the hydrometer down in the same level space each time you check it. When we used one he set it on top of the tank lid each time. Holding it at an angle can push off your results as well.

 

[ezy33]

IMO it's OK to mix your water in the tank at start up, after that Tomchong22 is correct always mix in a separate container. The hydrometer is sensitive to temperature, making sure the whole system is at the same temperature will give a correct reading. I had two different brands with two different readings. Took them to my LFS and they had a different reading from a third brand.

Letting is soak will free any sticky deposits and make sure that the arm swings freely before using. The main thing is to get the tank and the new water at the same salinity whether it's a bit high or low. A refractometer will give the correct reading and is not temperature sensitive. Good luck with your new system!

 

[ezy33]

Too more good points from Maya!

 

[Blakskall]

thanks for the advice, i think ive figured it out, the high reading was from an air bubble stuck to the needle. I think ive gotten it pretty close, im going to have a LFS check it before i buy any actual fish lol

 

[huma-huma]

Sorry for the double post but ..the Husband wants me to add that you also need to set the hydrometer down in the same level space each time you check it. When we used one he set it on top of the tank lid each time. Holding it at an angle can push off your results as well.

Sometimes a gentle tap or two will also help

 

[huma-huma]

Don't forget to cycle