Hydros AWC Help-salinity falling

[FishTacos2]

I set up my hydros to do AWC

I am using 2 DC pumps. One pumps water from the sump to a drain for 3 minutes (about a gallon). One pumps salt water in till it hits the water level sensor.

I was scheduled to do a gallon a day. When I do my salinity drops from 1.025 to 1.024 every 2 days and requires me to add about a cup of salt to my sump.

When the AWC is off the salinity remains stable for several days.

There is no siphon on the drain side. My replacement water was increased to 1.030 with no benefit.

Any ideas?

 

[Randy Holmes-Farley Verified Community Expert]

Did you check to see if they pump the same amount?

 

[FishTacos2]

Given that the trigger to stop the full pump requires the water enter the sump to the poi t of the fill sensor I cannot collect it to measure it

I watched it in action today
Drains and fills back up exactly the same as I would do manually…

 

[Mattiejay6]

sounds like your ATO is topping off more then your fresh salt water and the pumps need to be calibrated. The only thing that makes sense given your situation.

Work on calibration versus compensation because that’ll eventually creep imo

 

[Randy Holmes-Farley Verified Community Expert]

The effect you are noting in salinity is quite extreme. How much water are you changing each day?

I recommend about 1% daily and at that rate, adding no salt water at all would take a few days to see the effect you see.