Dosing the water change water?!

[CG2000]

Maybe I'm blind but I can't find clear info on this, would apprecitate your points of view!

Do you:
a. dose the clean water that you're putting in during a water change to your ideal parameters?
b. make the water change with RO water at correct salinity and temperature, then measure parameters and dose to adjust back to target?

To me, on a tank that is stable, it would make sense to do a.

If a. how would you go about dosing it?

Thank you!

 

[ndrwater]

I wouldn't dose anything to water change water prior to adding to your tank.
Water changes are typically to dilute or reduce things like nitrate and phosphate rather than adding to.
If you were to dose the big 3; Calcium , Alkalinity and Magnesium, you need a benchmark in your tank and adjust accordingly.
Dosing water change water is a good way to get things out of whack in a hurry.

 

[CG2000]

Ok, to be clear I was only suggesting adding Alk, Cal, Mag to the clean water, as these get negatively diluted by the water change. Otherwise you’re intentionally diluting the things you’re trying to keep stable.

 

[MikeReefs]

Really depends on the salt you are using. For example my salt (reef crystals) has higher Alk,Cal,Mag than my tank. So when I perform a waterchange I don’t dose for 2 days. Now if you are diluting the tank with salt less than your current tank I would simply figure out how much the salt contains and subtract it from how much you currently dose daily. Me personally I just wouldn’t dose at all the day your are doing the water change or just dose very little. That small drop more than likely won’t affect anything

 

[Randy Holmes-Farley Verified Community Expert]

Maybe I'm blind but I can't find clear info on this, would apprecitate your points of view!

Do you:
a. dose the clean water that you're putting in during a water change to your ideal parameters?
b. make the water change with RO water at correct salinity and temperature, then measure parameters and dose to adjust back to target?

To me, on a tank that is stable, it would make sense to do a.

If a. how would you go about dosing it?

Thank you!

What parameter is lower in your new salt water than the tank?

It’s fine to dose that way. I dosed magnesium
In new salt water rather than to the tank.