Why is my salinity so high?

[Terri Caton]

Hi everyone, new tank person here. My tank is 2 weeks old and I've had my diatom bloom. Right now I have in my tank:
One live rock
Some Reef Saver rock
Live sand
3 hermit crabs
1 skunk shrimp
1 peppermint shrimp
2 clown fish
1 royal gramma

All the fish and inverts are doing great!

Here are my water parameters:
Nitrate 0.2
Ammonia 0.5
Alkalinity 9.9
Temp 77
Salniity 1.030 + (cannot read any higher)

Why is my salinity so high? I used RO/DI water from my lfs and it was perfect at first. I've done one 10% water change since setting up the tank 2 weeks ago.

What should I do?

Thanks!

 

[hllb]

Have you been topping off with freshwater for evaporation?

 

[W1ngz]

Like hllb said, salt and everything else in the water doesn't evaporate, only the water does.

High salinity is also why your alkalinity is high.

Take out some tank water, replace it with clean RODI. How much depends on the tank volume, but it's ok, actually better, to not force the whole change all at once. Repeat a little each day until things are back to 1.026.

Good job on posting a full set of parameters when asking for help!

 

[BeejReef]

Why do you say your salinity "can not read any higher?"
All the above is excellent advise. Just be certain it's not user error or a bad refractometer or hydrometer before you try making changes in your salinity.

 

[Terri Caton]

I used distilled water when I realized it was high since my local lfs was closed. About 1.75 gallons.
My tank is 32 gallons.
I haven't really had much evaporation. Maybe that's because I have a solid lid?
I have some RODI water now so will try to change a little each day.
Thanks!

 

[Terri Caton]

I'm using a Red Sea Refractometer. I know how to read RI from doing it on gemstones. It was 0.126 at first so I know I'm doing it correctly.

 

[Mikedawg]

I'm using a Red Sea Refractometer. I know how to read RI from doing it on gemstones. It was 0.126 at first so I know I'm doing it correctly.

Can't imagine any reason for such a sudden rise in salinity unless it is a matter of invalid instrument testing. Always a good idea to recalibrate a refractometer; surprising how some get "out of whack" quickly.

 

[BeejReef]

Do you have a "fill to" line on your sump? Basically it's a piece of tape marking where you consider the system to be full.

You can fill your tank and sump with perfectly 1.026 water, but if you let it drop a half inch or an inch and don't top it up to as high as before, the salinity increases. I imagine you already know and understand this. Just being safe by suggesting. 1.030 is dangerously high. If it is really off the scale higher than that, you're headed for trouble pretty quickly.

 

[hllb]

Can't imagine any reason for such a sudden rise in salinity unless it is a matter of invalid instrument testing. Always a good idea to recalibrate a refractometer; surprising how some get "out of whack" quickly.

I did just see a post about a similar issue and the Red Sea refractometer turned out to be bad.

The other option is that you didn't rinse your pipette well and salt dried inside the pipette. Test a few more times after rinsing pipette thoroughly with RODI water to make sure there's no residual salt in there.

 

[MnFish1]

Like hllb said, salt and everything else in the water doesn't evaporate, only the water does.

High salinity is also why your alkalinity is high.

Take out some tank water, replace it with clean RODI. How much depends on the tank volume, but it's ok, actually better, to not force the whole change all at once. Repeat a little each day until things are back to 1.026.

Good job on posting a full set of parameters when asking for help!

The alkalinity is not high - depending on what salt was being used. There is no way to know - First - what are you using to test your salinity - and is that method documented with another method - and calibrated. Second - are the things in yoru tank showing any signs of problems from 'increased salinity'

 

[MnFish1]

I'm using a Red Sea Refractometer. I know how to read RI from doing it on gemstones. It was 0.126 at first so I know I'm doing it correctly.

How often were you doing it - every day - every week? What could have possibly caused it - Were you topping off with salt water - or 'water'. ? There is no way salinity can increase except for 1. Mistakes in measurements 2. Mistake in water replacement (mixing saltwater), 3. Replacing evaporation with salt water rather than 'water', 4. not replacing water.

 

[lyscer]

I have a red sea refractometer and it has to be calibrated prior to every use or it gives bad readings. Been like this since day 1. When I first purchased it I reached out to red sea an inquired and they person I spoke with said it needed to be calibrated prior to each use, so this is apparently the standard protocol for these ones. It was super annoying at first but just part of my process now.

 

[Terri Caton]

Yup. You guys who said calibration are correct! It's off. I've only used it about 5 times so didn't even think of that!
Thanks all!

 

[Terri Caton]

The alkalinity is not high - depending on what salt was being used. There is no way to know - First - what are you using to test your salinity - and is that method documented with another method - and calibrated. Second - are the things in yoru tank showing any signs of problems from 'increased salinity'

My fish and invertebrates are as happy as could be! No coral yet. The tank is only 2 weeks old so...
I did check the calibration (Red Sea Refractometer) and it was off.

 

[Terri Caton]

I have a red sea refractometer and it has to be calibrated prior to every use or it gives bad readings. Been like this since day 1. When I first purchased it I reached out to red sea an inquired and they person I spoke with said it needed to be calibrated prior to each use, so this is apparently the standard protocol for these ones. It was super annoying at first but just part of my process now.

Good to know. It's new (used maybe 5 times) so I never even thought of that.

 

[Terri Caton]

Do you have a "fill to" line on your sump? Basically it's a piece of tape marking where you consider the system to be full.

You can fill your tank and sump with perfectly 1.026 water, but if you let it drop a half inch or an inch and don't top it up to as high as before, the salinity increases. I imagine you already know and understand this. Just being safe by suggesting. 1.030 is dangerously high. If it is really off the scale higher than that, you're headed for trouble pretty quickly.

Thanks for responding. That makes sense but I'm new to this so the obvious things aren't always so...obvious. The refractometer definitely needs calibrating.