yes dosing part c from tropic marin seems to keep my tank balanced quite nicely

I Like Salifert it seems to be pretty good and its based on colour change not turbidity

The problem is Salifert stopped making the Potassium test kit.

The last time our Salifert supplier was able to get it was March 2014. :cry:

Never thought about it until I used Zeovit balance K. I started seeeing better coloration and more grow on SPS. So I am planing on purchasing a test kit now.

I have been using Kent Trace Elements which has K in it, as well as a bunch of other stuff. Not sure if it helps, but since I just use IO for salt, thought a few extra elements supplements can't hurt. And it's cheap. My SPS growth and color has been good.

I always had way too much trouble with the turbidity style test kits - found it incredibly challenging to get an objective reading. I kind of gave up on testing for it.

do you need to test if you're dosing zeovit PIF? I would assume so since it's still a form of potassium.

hard to say but possibly not , alot of foods are high in potassium as well some salts are to :)

I only dose for cal/alk, anything else is replaced by twice monthly water changes, tho all my sps an lps are small colonies or frags. If my reef was full of large corals then I could maybe see the need to dose more elements, still a 25% water change with good a good salt mix should replace most minor elements IMO.

I test a couple times/year just to know what's going on

I'll be testing it a few times in the near future as I'll be switching from 10% weekly WCs to 25% bi-weekly