Using old salt water... opinions requested

[shinninja]

Hey everyone. I have an idea i wanted some opinions. I have an automated water change done daily (my preference). About 2 gallons a day. Comes out of a 200 gallon tank. Since my tanks water parameters are usually on target, would it be bad to use that water to top off a fish only aquarium? Is that too crazy? The other tank is 55 gallons. I was thinking of adding those two gallons that are removed daily to the 55gal tank. Im just trying to be very water efficient. Dont really have to do it. Just an idea. What do you folks think?

[MattDiaz]

I would say that you'd get into a hypersalinity situation quickly, since the waste water is salted.

[Mmiller40gt]

You could use it to change water in the FO. Cant top off with salt

[shinninja]

Im thinking of having the old water go directly into the FO tank. It would be sitting around.

[Mmiller40gt]

Water evaporates and leaves the salt. If you add saltwater the salinity will increase. The more you do this the higher your salinity will get. Ever heard of the dead sea? That what will happen when your salinity get too high. You top off an aquarium with FRESH water.

[shinninja]

Well good thing I asked.