Kmore-
I'm a newbie running just a few months ahead. Our perspective, in combination with the seasoned experts here on R2R, may present to a similar chord.
My daughter and I ran a 55g tank for 4+ years with many LPS - Duncan's, Frogspawn, Xenia, GSP, etc. We started a new 125g in September and that was the first time we even considered Alk, Ca, & Mag. It was also the first time we began keeping a tighter control on nitrates and phosphates. Water changes were not keeping up with Alk/Ca demand. We tried Kalk in our ATO, but found that our tank had higher demand and required 2 part in addition. In the last few weeks, we weaned the Kalk from the system to focus on 2 part only. We started using Red Sea Foundation A / B and then switched to BRS (Randy's) 2 part in December. We're still dosing manually, but we bought a dosing system 2 weeks ago and have been running tests since to assess the consistency and accuracy. We'll likely set it up next weekend. I compare the dosing systems to an aviation / marine auto pilot. We can steer a boat or a plane manually, but you'll never maintain a course as stable as the machine.
We started our venture with the idea we would take water samples to our LFS for testing. The inconsistency (and hassle) we found did not inspire confidence. We ended up reading the forums about chemistry and testing and opted for a slightly mixed bag of testing equipment. We use Hanna Instruments for Alk, Ca, & Phosphate (ULR) and NYOS for Mag & Nitrates. We still don't have a pH meter... Once we began a regular testing regimen, the patterns were clear.
FWIW- my daughter and I said we'd NEVER test monthly and get into dosing... now we test Alk daily (that'll likely back off to weekly soon) and all parameters weekly. As we've gotten to know our tank, I think we'll be able to assume a monthly or bi-monthly testing schedule soon. We enjoy it and the ability to predict the results based on patterns and observations is very satisfying.
We've learned A LOT from R2R over the last several months. We have a lot yet to learn, but we're in... entranced.
As a result, the health and success of this tank is a whole different world. Our fish, corals, and inverts are thriving (with only the occasional set back). We have large colonies of Duncan & Frogspawn, but, in the SPS / more advanced coral categories, we added Red Setosa, Sunset Monti, Hawkins Enchinata, Cali Tort, Maze Brain, Leptastrea, Cyphastrea, Blastos, Palys, Zoas, etc.
We now have reefer's disease. Hi, my name is Matt and I'm a reefer... Come on in, the water's warm. About 78 to be exact.