Dosing

[Eoka]

Right now I dose kalkwasser and I have something for magnesium. It's works fine. Keeps my ph and kh stable. But I do water changes to replenish the other stuff that corals need. But whenever I do a water change it 0 my nutrient levels having negative effects. So I want to know if I should switch to a product like all for reefs so I don't have to do water changes and what should I use for lowering and raising nitrates? I use gfo for phos.
Thanks

 

[Eoka]

I'd like a cheap option if that's possible