Water Changes

Kasey Grohowski · Jan 25, 2019

I've seen on other websites some people don't add salt to the new water they're adding during a water change and I've seen people that do. I'm planning on doing the trash can with a heater and powerhead method, just not sure if I should add salt to the new water or not.

Ruben's Reef · Jan 25, 2019

If you are doing a water change, you will need to add salt to the water because you're replacing the water, like 10%. You will need to match the salinity on your DT. Now, for top off you don't need to add salt. I have a gravity ATO that refill the water that evaporate keeping the salinity stable.

reacclimating 2 the hobby · Jan 25, 2019

I'm a bit confused here. Your ATO should be fresh RODI water, but if you are performing a water change(10-20% or more) then you should be adding back the same amount of saltwater that you removed. Unless you are attempting to lower your salinity.

IslandLifeReef · Jan 25, 2019

Kasey Grohowski said:
I've seen on other websites some people don't add salt to the new water they're adding during a water change and I've seen people that do. I'm planning on doing the trash can with a heater and powerhead method, just not sure if I should add salt to the new water or not.

If you are doing a water change, you definitely want to add salt to bring the new water to an sg of 1.024 -1.027.

I think you are looking at people topping off their tanks with freshwater. This is totally different than a water change. They are adding water to account for evaporation. Salt doesn't evaporate, so to keep the SG constant, you only add freshwater.

If you only added freshwater during a water change for a saltwater tank, it would eventually become freshwater, but everything would die first.