ATO disabled for 2 days.... salinity didn't change?

[Reefkeepers Archive]

Anyway I accidentally left the ATO off for 2 days, caught it after I checked the top-off log. Sump water level dropped only about 1 inch. Checked the salinity and it didn't change???? I always calibrate my refractometer with RO before every use so I don't think it was an error. Though is this right? Or is my refractometer off?

 

[Court_Appointed_Hypeman]

If the level only dropped by an inch, it probably wouldn't be a measurable change unless its a very large return chamber compared to the volume of the rest of your system.

 

[Lavey29]

Normal evaporation followed by RODI top off does not change salinity. Removing saltwater from the tank manually and replacing RODI will lower salinity.

 

[randomfishdude]

There would be no change.
My ato broke. So when I upgraded my tank I didn't have one. My sump lever drops about 3 inches and I refill it every 4 days at about 4 gallons. No sal change.

 

[Wave Whisperer]

What's your size of tank and total water volume? These are crucial in determining fluctuations. Unless if you are running a nano, a larger tank would go almost unnoticed with salinity swings in regards to missed ATO top ups. I have been guilty of this as well. Forgot to turn back on my ATO after maintenance for at least 4 days before I noticed it. Salinity remained at 35ppt for me. My total system volume is around 170gal.

 

[Reefkeepers Archive]

What's your size of tank and total water volume? These are crucial in determining fluctuations. Unless if you are running a nano, a larger tank would go almost unnoticed with salinity swings in regards to missed ATO top ups. I have been guilty of this as well. Forgot to turn back on my ATO after maintenance for at least 4 days before I noticed it. Salinity remained at 35ppt for me. My total system volume is around 170gal

System is 120 gal

 

[Lavey29]

My 15000g saltwater pool loses 10s of gallons each day in summer through heat evaporation and is replaced by tap water auto fill. The salinity level does not change through normal evaporation. Now when kids splash a bunch of water out of the pool over the course of a month then I might need to add a bag of salt here and there over the summer.

 

[randomfishdude]

My 15000g saltwater pool loses 10s of gallons each day in summer through heat evaporation and is replaced by tap water auto fill. The salinity level does not change through normal evaporation. Now when kids splash a bunch of water out of the pool over the course of a month then I might need to add a bag of salt here and there over the summer.

I need to see that pool.

 

[Mr. Roboto]

It takes a lot more water than folks think to evap before a measurable change occurs.

 

[Randy Holmes-Farley Verified Community Expert]

Refractometers are not very precise and won’t detect small changes well.

 

[fishyjoes]

You can use the "Resulting Salinity Calculator" from Hamza's Reef to see how much the evaporation effect is

https://www.hamzasreef.com/Contents/Calculators/ResultingSalinity.php

At 120 gallons, each gallon evaporated raises salinity by 0.294 ppt (according to that calculator at least)

 

[Reefkeepers Archive]

You can use the "Resulting Salinity Calculator" from Hamza's Reef to see how much the evaporation effect is

https://www.hamzasreef.com/Contents/Calculators/ResultingSalinity.php

At 120 gallons, each gallon evaporated raises salinity by 0.294 ppt (according to that calculator at least)

Just used it, not much of a difference at all, thanks!

 

[Lavey29]

I need to see that pool.

I'll pm

 

[Reefering1]

I'll pm

Beautiful pool!! But I believe you missed a zero or 2.. 15000 gallon pool is a typical in ground pool. That looks much bigger

 

[Reefering1]

They wiped that quick

 

[Lavey29]

They wiped that quick

I deleted it and sent a PM instead. But thank you