Calculating Salt Addition After Salinity Drop

[dangles]

I’m not sure if I’m in the right forum or not but regardless…

I’m away from home on a long trip and have a neighbor watching my tank. He’s not a reefer. I had to show him how to do some basic measurements.

He reported to me today that after a week of me being gone, the salinity is down to 31 ppt. I need to walk him through how to slowly bring it back up.

Is there a way to calculate how much total salt he needs to add in order to bring the salinity back up to 35 ppt?

The system is 120 gallon total and I use TMP salt if that matters.

And will reduced salinity affect the reliability of the alkalinity, NO3/PO4 readings?

 

[Jekyl]

How exactly did the salinity level drop? This could only be done through water changes or excess top off.

 

[Pistondog]

How does the salinity go down that much in a 120 gallon tank in a week.
Do nothing, or have him take a sample to the lfs for verification.

 

[Pistondog]

If it is real, put saltwater in the ato to gradually raise salinity. Check daily.

 

[dangles]

How exactly did the salinity level drop? This could only be done through water changes or excess top off.

Yeah I’m working on sorting that out. It can only be a leak (which he hasn’t noticed) or a mismatch in my AWC in/out lines. I’m using a DOS pump for AWC. I shut it off remotely in case that’s the issue.

I’m also having him double check his reading of course, as well as check it against the reference solution I have.

 

[threebuoys]

Look at the calculators post in the sticky in the fish diseases forum.

 

[Pistondog]

Thats over a 10% change or more than 12 gallons on the floor if a leak.
How much do you awc?

 

[dangles]

Thats over a 10% change or more than 12 gallons on the floor if a leak.
How much do you awc?

I just had him check again and also check against the reference solution. Sounds like his first reading wasn’t quite accurate. He said 35 with the reference solution, and tank recheck is 33. Better than 31!

 

[Pistondog]

What is he checking with, if plastic swing arm hydrometer, make sure he shakes off the bubbles

 

[Randy Holmes-Farley Verified Community Expert]

At 33 ppt, best to do nothing while you are away. :)

 

[tsharpe291]

Yeah I’m working on sorting that out. It can only be a leak (which he hasn’t noticed) or a mismatch in my AWC in/out lines. I’m using a DOS pump for AWC. I shut it off remotely in case that’s the issue.

I’m also having him double check his reading of course, as well as check it against the reference solution I have.

I had that issue using dos for awc, tubing was loose enough that they weren't pulling/pushing the same amount. luckily I caught it before it got out of control