Low salinity

[Michael v]

I have a 65 gallon fish and clean up crew. Also 25 gallon sump. My salinity is usually 1.024 or 25. I’ve been doing 10 percent water changes every week. I tested my water and got 1.020 should I do bigger water changes? My system has only been up since November. Or should I do like I’ve been doing?

 

[Crabs McJones]

What are you using to measure salinity? Unless your water change water isn't at the correct salinity when you put it into your tank, your salt content shouldn't be changing. My guess is either the tool you're using to measure salinity is incorrect, or your water change water isn't at the salinity you think it is.

 

[Rlreefing]

your salinity does not have to change when doing water changes. The scale of the water change does not matter for salinity, it is your testing method. When doing water changes it is important to insure that the salt is fully dissolved in the water( no residue on the bottom of the mixing bucket) and that you check the tank salinity and match the two unless you are intending to raise or lower the salinity respectively. If you desire to raise you salinity, add more salt to your next water change. Space out the raising 2-3 weeks to reduce stress on fish and other tank mates.

larger water changes may be required if levels such as ammonia, nitrate, nitrite, or phosphates are above acceptable levels.

 

[3dvice]

Start mixing your water change water to a higher salinity like 1.030 and use those to slowly bring the tank salinity up

 

[Qasimja]

how are you testing your salinity?

 

[Michael v]

how are you testing your salinity?

I use brs refractometer. I recalibrated to 35ppt or 1.0264 it was right on. I wonder if my ato has been adding a lot with the hot weather. My temperature in my display has been 79 degrees. My ammonia level is at 0 my nitrate was around .5 my ph is 8.2 and kJ around 7

 

[lapin]

Salt will not evaporate. As water evaporates the water will get salty. The ATO putting in fresh water will only bring salinity back to what is was before evaporation.
My thinking it is either a testing error or you put in fresh water instead of salt water when doing a water change.
Maybe your skimmer skimmed out a ton of water into a remote container?

 

[Michael v]

Salt will not evaporate. As water evaporates the water will get salty. The ATO putting in fresh water will only bring salinity back to what is was before evaporation.
My thinking it is either a testing error or you put in fresh water instead of salt water when doing a water change.
Maybe your skimmer skimmed out a ton of water into a remote container?

I think the way I’ve been doing my saltwater mixing may be the problem. I use reef crystals and mix up 25 gallons at a time. I’ve been putting in 12.5 cups of salt. I mix it over night with a circulation pump and air stone. The problem is I use a large ice chest to mix in. In the morning it sometimes gets up to 85 degrees. Now I think I’ll only mix what I need in a rubber made trash can. I’ll mix as instructed 1/2 cup per gallon. Of course I’ll test the salinity and make sure my temperature is around 77 degrees. Live and learn. Thanks for your advice.

 

[Hemmdog]

How often are you dumping your skimmer cup ?

 

[Michael v]

How often are you dumping your skimmer cup ?

Twice a week

 

[aqua_code]

triple check your refractometer before you do anything. You either have a leak or your last mix was much lower salinity.

 

[Michael v]

Update I did a 10 percent water change bringing the salinity to 1.024. I’m going to have to be more diligent with keeping track of my water perimeters.

 

[Mike konesky]

Top off with salt water.

 

[leedsrhinojohn]

I should really check that refractometer and buy a second one as something to check against,
I have 2 of every test kit, that way if a reading seems off, you have something else to check it against. Going from 1,020 to1.024 in a 10% water change says to me your readings are wrong as the new saltwater would have to extremely high to raise it that high, also if your readings are correct then it is dangerous to the inhabitants to raise sg that amount instantly.

 

[Michael v]

I should really check that refractometer and buy a second one as something to check against,
I have 2 of every test kit, that way if a reading seems off, you have something else to check it against. Going from 1,020 to1.024 in a 10% water change says to me your readings are wrong as the new saltwater would have to extremely high to raise it that high, also if your readings are correct then it is dangerous to the inhabitants to raise sg that amount instantly.

That’s a good idea will try that.

 

[leedsrhinojohn]

On another note regarding calibration, when calibrating any testing equipment always calibrate using solution which is closest to your target aim. for example, your refractometer, many people calibrate at zero using ro/di water, you are testing for 1.024 so you need to calibrate at 1.024 or as close as you can to that (most calibration fluid is 1.026).
Calibrating at zero means your refractometer is good for testing zero not 1.026.
Example, your car speedo is at zero when you stop but is it accurate when your car is doing 70? Mine isn't, Its accurate at zero but when it shows 70 im actually doing 66.

 

[Shredder99]

I think the way I’ve been doing my saltwater mixing may be the problem. I use reef crystals and mix up 25 gallons at a time. I’ve been putting in 12.5 cups of salt. I mix it over night with a circulation pump and air stone. The problem is I use a large ice chest to mix in. In the morning it sometimes gets up to 85 degrees. Now I think I’ll only mix what I need in a rubber made trash can. I’ll mix as instructed 1/2 cup per gallon. Of course I’ll test the salinity and make sure my temperature is around 77 degrees. Live and learn. Thanks for your advice.

Hi Neighbor!, I am over the hills in Denver and I have the same issue - decreasing salinity over time, particularly in the summer months. Remember that our humidity in the summer is around 35%, so we will have a lot of evaporation when compared to other parts of the country, Yes, salt doesn't evaporate, but I get a lot of salt creep around the lid, wires, etc. I mix mine five gallons at a time and add a little extra (about 1/4 cup) salt mix in every other bucket. I also suggested getting some calibration fluid for the refractometer or checking the expiration date on yours if you already have some to make sure your reading will be accurate. I bought a cheap hygrometer as a secondary tester and use both to test salinity. As long as I am coming away with the same readings, I have peace of mind.

 

[Michael v]

Hi Neighbor!, I am over the hills in Denver and I have the same issue - decreasing salinity over time, particularly in the summer months. Remember that our humidity in the summer is around 35%, so we will have a lot of evaporation when compared to other parts of the country, Yes, salt doesn't evaporate, but I get a lot of salt creep around the lid, wires, etc. I mix mine five gallons at a time and add a little extra (about 1/4 cup) salt mix in every other bucket. I also suggested getting some calibration fluid for the refractometer or checking the expiration date on yours if you already have some to make sure your reading will be accurate. I bought a cheap hygrometer as a secondary tester and use both to test salinity. As long as I am coming away with the same readings, I have peace of mind.

Thanks I think your right I’ve been mixing twenty five gallons at a time in one of those igloo ice chest that holds 35 or 40 gallons. I usually only use 8 to 12 gallons for my water change. I then store the rest. So this last water change I only mixed 9 gallons using 8. My water is testing good now at 1.024. I’m going to keep an eye on it testing every day. I do believe salt creep is the reason for the drop because my protein skimmer has a lot on the sides. Thanks for your help.