Water Changes plus dosing

[Anthrax15]

I will be using an auto doser for dosing Ca, Mg, and Alk with my next tank build but I had a question regarding when I do water changes. Tank will be roughly 70g including sump and I will most likely be doing 10g WC's every week or two.

1. Once I figure out my daily dosing for the tank, what will happen to CA, MG, and ALK when I do a water change?
2. Will I need to increase my dosing for that day?
3. Hypothetically, won't my main three trace elements slowly go down to numbers provided in the salt I use if I don't keep them within that range?

 

[Doctorgori]

I’ve never worried about that ...... perhaps change the H20 and make manual adjustments that day ...I test Alk 2x week, Phos 1x/wk. mag & Ca after every water change (I avg H20 chg about 10% every 2wks)

 

[homer1475]

Easiest way is to test your new mix, and add or remove elements to match your display. This way you don't have to mess around with figuring out the dosing change.

 

[Randy Holmes-Farley Verified Community Expert]

Hypothetically, won't my main three trace elements slowly go down to numbers provided in the salt I use if I don't keep them within that range?

Up or down toward the water change, yes. But the effect is small unless the change is very large.