New to reefing and need some advice

[Joel Franco]

I do have an ATO but I noticed that if I top with RO/DI water that it messes up the salinity. Do you top off with saltwater?

 

[Joel Franco]

I keep a log on the testing done on my freshwater tank and the reef tank. I like to compare the numbers and see the differences after a water change or a new coral or fish addition.

 

[DannyB]

You should top off with rodi. evaporation is only going to take water which would steadily increase the salinity over time if no water was added. So adding saltwater will increase the salinity. The only time I ever use saltwater to top off is if i am needing to increase my salinity. This is a nice slow way to increase the salinity.

What type of issue are you having with the salinity when using rodi to top off? What are you checking your salinity with?