best ways to control calc, mag, alk?

[z_dano]

I would love to have a larger sump, sadly this is the biggest I can fit, it's a column tank so I have little room underneath.
I wish I planned it's location better, an external sump will not work unless I run it through the wall into the matter bed room (that may not go over well). I love the look of where it is but it's functionality stinks. I can give the shorter time between changes a shot. I like the idea.