hardness

Hi! Are there any relationships between Ca or HCO3 and N,P, micro ferts? I mean if I have 5 dKh and 5 gH need I dose more then if I would have 1dKh and 5gh? At the same time in both cases pH is stable and around 6,7. Thanks a lot!

I came across this article talking about how salvinia molesta can "suck up" lead and mercury, if I understand it correctly. https://www.ijcmas.com/abstractview.php?ID=2236&vol=6-4-2017&SNo=325 Was wondering if that happens magnesium and calcium too. Although I personally have salvinia...