Triton thus far seems to be working
I purchased the Triton Core 7 elementz as they don't need diluting with RO and are therefore very easy to dose via syringe or dosing pump. I'm currently dosing only 2ml of each per day and have the following observations:
My corals are growing (at last) and displaying some nice colour and look healthier (e.g. my war coral was receding, but has now plumped up and is spilling over the frag plug side

and my plating red monti has developed a nice white growth rim

).
My skimmate is cleaner - which according to the boffins that provide it, means that it has now taken hold of my system and is doing what it's supposed to do

(i.e. there are less dissolved organics, etc. for it to skim).
No more water changes!!!!!!!

(until the ICP test tells me otherwise that is

).
Alk is stable....but is too high (the target for Triton is 8 - mine is 10.5), so the solution is to bring it down very slowly by reducing the dosage of the elementz, however, their guide says that stable Kh is the key (so I may just wait to see what the ICP tests tell me).
Note: The guide does state that converting a mature system will generate elevated levels and the solution is to reduce Kh very slowly.