Water change and evaporation

[GoLowDrew]

I moved the location of my tank. For some reason, it seems the water seem to evaporate a bit faster.

That's not my question.

Let's say my water change is 3 gallons old out, 3 gallons new in .

With evaporation, I only have to take out 1 gallon of old, and put 3 gallons new in.

**The numbers are just an example to set up my question. I don't loose 2 gallons of water between changes.**

My question is, then should I be taking out more? Does water lost via evaporation the same as me taking it out?

[Virtuoso]

No, it is not the same. When the water gets evaporated it leaves the salt behind. When you take water out you take the salt with you.

So doing what you are suggesting would make the salinity jump all over the place.

Rule of thumb - If the water is evaporating, replace with normal RODI water. If the water is taken out or somehow "lost" without evaporation, then fill with salt water that matches your current salinity.

[clarky11]

whatever amount of gallons you remove for a water change the same amount must be put back in.