Auto top off with salt water

[masonicman]

Does anyone with an ATO put a little salt in their fresh RO/DI water?
The reason why I ask is because. I notice my salinity dropping the more the water is replaced. My skimmer is pulling out alot of skimmate also.

 

[sslak]

This is probablye due to salt creep collecting on various things instead of staying disolved in your water where you want it. Mixing your water-change water a tiny bit stronger would even it out. You could also try putting a small amount of salt in your top-off. That poses the exact opposite problem you're facing right now, which would be that your salinity will slowly raise as the top-off water is added.

 

[Randy Holmes-Farley]

Adding back salt water to replace skimmate is appropriate. Skimmate has about the same salinity as the tank. It is certainly fine to put a little salt into a typical top off system, as long as you are not otherwise using limewater in it. Whether any particular system can handle it may depend on the details of how it is made, but I expect most are fine.

 

[masonicman]

I just have a 10 gallon tank under with fresh RO/DI water in it.

 

[cfarrow2]

I sometimes put a little salt in my top off. What I haven't done is check the Ph of the top off water. You may want to if you have some sensitive corals. Not sure what just a little salt will do, however.