Salinity off

[qstorm]

Hi All,
I have been having multiple issues during the cycle of this tank, but seeing that i am a trial and error person i have been trying to rectify the issues on my own.
I set up the new apex fusion system, and my salinity was reading 19.9ppt from the probe. When i initially mix the water it was around 33-34ppt or 1.024- 1.025. The reason i say around is because my refractometer didn't come with calibration fluid. I used RO water to calibrate it, so been a newbie fi will give and take that it may be off just a bit until my calibration fluid arrive. With that said i thought the probe would be more correct.
i kept adding salt, using various methods (i have 2 clown fish, they are fine..they seem to withstand anything, but don't plan on harming them) and the probe kept increasing.
This morning i found my old hydrometer and tested the salinity. It was reading 1.037, so i use the refractometer and the reading was the same , so i will assume my probe is off. The probe is now reading 31.8 ppt.
Any reason why my probe would be off by so much? and how do i lower the salinity?

Thank you

 

[Crabs McJones]

New probes need to be calibrated. You cannot assume that they are calibrated correctly from the factory. Also using a calibration fluid is best for your refractometer instead of RO/DI water. Best way to lower your salinity is going to be do to a series of small water changes with water mixed up to the salinity you want it at, or take out tank water and replace it with ro/di water slowly until your salinity comes down to where you want it.

 

[RocketBunny]

Hi All,
I have been having multiple issues during the cycle of this tank, but seeing that i am a trial and error person i have been trying to rectify the issues on my own.
I set up the new apex fusion system, and my salinity was reading 19.9ppt from the probe. When i initially mix the water it was around 33-34ppt or 1.024- 1.025. The reason i say around is because my refractometer didn't come with calibration fluid. I used RO water to calibrate it, so been a newbie fi will give and take that it may be off just a bit until my calibration fluid arrive. With that said i thought the probe would be more correct.
i kept adding salt, using various methods (i have 2 clown fish, they are fine..they seem to withstand anything, but don't plan on harming them) and the probe kept increasing.
This morning i found my old hydrometer and tested the salinity. It was reading 1.037, so i use the refractometer and the reading was the same , so i will assume my probe is off. The probe is now reading 31.8 ppt.
Any reason why my probe would be off by so much? and how do i lower the salinity?

Thank you

To lower salinity, you will have to scoop some water out of the tank, and slowly replace it with freshwater (or RO/DI in your case)(that is so, because salinity is the measure of salt per water in ppm or %. Replacing an amount of saltwater with freshwater will lower the salinity because there will be more free water molecules than salt+water molecules... the refractometer will read a lower salinity because now the amount of salt per freshwater is smaller than before). Once it mixes in, it will rapidly lower your salinity (so you will have to constantly measure to make sure that you don't over-do-it). Set up a dripping system for this as it will let you shut off the drip at any moment (lets say once your salinity reaches norm levels). A drip system is where you have your container (cup, bottle, whatever) with freshwater and a small tube with a knot going out of it. Suck on the end of the tubing to get rid off all the air, and water will start flowing down there, the knot will help you regulate how much drips you get per second (I recommend 3-4 drips). Make sure that it is dripping into a high flow area for good mixing. Once that is done, start measuring with your refractometer every 5 minutes, and once your salinity reaches normal levels(1.024-1.026), stop the drip. (Also... remember that we scooped out some water? If the drip doesn't bring the water level back up to what you had before, simply mix some salt-water with the same salinity and pour it in until your water level is brought back up to where it was)(And here is the opposite - if the drip ends, and the salinity hasn't lowered to where is is supposed to be, simply add freshwater to your container, and re-start the drip)

Now about the probe. Does it say anything about calibrating the apex-fusion probe on the instructions? Try to see if there is any dirt/or/damage on the sensor... and if what - send it back where you bought it and exchange it.

 

[qstorm]

Thank you for the response. The probe came with a calibration solution which i used to calibrate it. It said it was successfully calibrated. The same thing happen to the PH probe. Its reading 7.8 but with both my test kit its reading 8.2

I ordered new calibrating solution for, the salt and ph probe as well as the refractometer.

I have a drip system which i used to up the salinity, so i will use it with ro/di water to lower it.

Thank you,
Q

 

[chipmunkofdoom2]

If the hydrometer and refractometer agree, I would trust that number. Even though freshwater is not the ideal way to calibrate a refractometer, it's likely close enough. The fact that it agrees with your hydrometer leads me to believe that these two measurements are correct.

I would pick up a bottle of calibration fluid from Bulk Reef Supply or another vendor. Or, if you have a 2L soda bottle, you can make your own. The salinity standard will be correct, and that can then be your baseline.

 

[qstorm]

If the hydrometer and refractometer agree, I would trust that number. Even though freshwater is not the ideal way to calibrate a refractometer, it's likely close enough. The fact that it agrees with your hydrometer leads me to believe that these two measurements are correct.

I would pick up a bottle of calibration fluid from Bulk Reef Supply or another vendor. Or, if you have a 2L soda bottle, you can make your own. The salinity standard will be correct, and that can then be your baseline.

Thank you,
I removed 10 gallons of water and replaced it with 10 gal of RO water and it came down a little. I will keep doing it in small amount until i get the right salinity. I guess i have to recalibrate the salinity probe, cause it went from 31 to 29 after the water change