I never used the pickling lime much Tony, so cant comment on it. Seems like a lot of aquarists in the US are though. I use Ben,s kalk. Good grade and a decent price. I believe Quinn also sells it at Prairie Reef Supplies. Before that I always used ESV.
If you wish to discontinue the kalk and are happy with ph levels and the co2 reactor, then just use a calcium additive to bring the level up. It should not effect the alk. The co2 reactor then can be set to keep both at par.
I also use the kalk to precipitate the phosphate but have no idea if its doing that.
