Best way to fix long time elevated salinity?

[aaron186]

I recently discovered that my Hanna salinity checker, despite frequently calibrating is off by about 2-3 and my 35 target was actually about 38 when checked on a Milwaukee digital refractometer and confirmed with my buddy’s TM hydrometer. My guess is it’s been high for a while if not the entire life of my 2 year old tank. My acros are doing OK but the color hasn’t been optimal.

I’m doing autowater changes of 1.5 gal per day in a 100 gal system. So a little over 10% weekly.

Should I just remove water and top it off with RODI a few times over the next week to fix? Or should I lower the salinity in my auto water change and correct this slowly over the next 1-2 months? I just mixed a new batch of salt water (50 gallons) that is measuring at 32 ppt (1.024 sg) currently that I need to add salt to still. I’m wondering if I shouldn’t?

 

[Randy Holmes-Farley]

I’d remove about 1% daily and replace by ro/di. That might be done by the AWC by stopping the new water uptake, and allowing an ATO to replace it. Or just drop the salinity in the AWC.

 

[aaron186]

I’d remove about 1% daily and replace by ro/di. That might be done by the AWC by stopping the new water uptake, and allowing an ATO to replace it. Or just drop the salinity in the AWC.

Thank you doc. I’d prefer not to mess with the AWC too much because the lines are pretty long and priming them was a challenge. I think I’ll just pull a gallon a day off from a bucket and use the ATO to replace it.

 

[Randy Holmes-Farley]

Thank you doc. I’d prefer not to mess with the AWC too much because the lines are pretty long and priming them was a challenge. I think I’ll just pull a gallon a day off from a bucket and use the ATO to replace it.

Sounds good!

 

[aaron186]

I’d remove about 1% daily and replace by ro/di. That might be done by the AWC by stopping the new water uptake, and allowing an ATO to replace it. Or just drop the salinity in the AWC.

Perhaps a stupid question. I’m now using the Milwaukee digital refractometer and it has SG and PPT as well as PSU. I know the gold standard is 35 ppt or 1.026 sg. Which one should I measure/use? I’m buying a TM hydrometer to make sure it’s calibrated on occasion

 

[Randy Holmes-Farley]

Perhaps a stupid question. I’m now using the Milwaukee digital refractometer and it has SG and PPT as well as PSU. I know the gold standard is 35 ppt or 1.026 sg. Which one should I measure/use? I’m buying a TM hydrometer to make sure it’s calibrated on occasion

Ppt and psu should read the same. Sg is also fine, with 35 ppt = 1.0264, and the hydrometer read in sg, correct?

 

[CHSUB]

Perhaps a stupid question. I’m now using the Milwaukee digital refractometer and it has SG and PPT as well as PSU. I know the gold standard is 35 ppt or 1.026 sg. Which one should I measure/use? I’m buying a TM hydrometer to make sure it’s calibrated on occasion

Yes, It is confusing. As Randy noted it should be the same, but it isn’t. I personally do PSU at 35 which reads 36 PPT and 1.027. However my ICP came back at 35.2 PSU.

 

[aaron186]

Ppt and psu should read the same. Sg is also fine, with 35 ppt = 1.0264, and the hydrometer read in sg, correct?

Yes hydrometer is in SG

 

[Fish Fan]

I have a love my Milwaukee digital refractometer. I keep mine set on PPT, and double check it with the TM hydrometer at 77 F. I had the same problem with a Hanna salinity checker pen, but mine read about three points low, even after calibrating.

 

[aaron186]

I have a love my Milwaukee digital refractometer. I keep mine set on PPT, and double check it with the TM hydrometer at 77 F. I had the same problem with a Hanna salinity checker pen, but mine read about three points low, even after calibrating.

My issue with the Milwaukee is that I calibrate it and run the test and get 34. Then press it again and get 35. And then again and get 34. But at least it’s closer than the Hanna

 

[Fish Fan]

My issue with the Milwaukee is that I calibrate it and run the test and get 34. Then press it again and get 35. And then again and get 34. But at least it’s closer than the Hanna

Hmmm, I don't have that problem, but admittedly the Milwaukee is not the most accurate or precise way to measure your sanity. Personally, I can't get past how easy and convenient it is to use, so I continue to use it