Hey TFP, just taking a few minutes of unproductive work time and putting it back into the TFP community.
Love the site, helped me out a lot in pointing out the right direction such as getting a professional test kit. I just wanted to give other people insight to what I found. Blue devil has a good kit (with Alkalinity, calcium harness and CYA tests) but no FAS-DPD, and at first look, I kept debating to shelling out 20 bucks just for the FAS-DPD if it was worth it. what I found is that FAS-DPD is definitely needed when you have problems (ie algae) and need to get the right chlorine shock value. So shell out the extra bucks to get the complete kit.
Second The pool math is a good tool, but I don't think it can calculate precisely the amount of chemicals (because possibly it doesn't account for all the minerals differences in the pool and their effect on chemistry).
What I found the best thing to do is to use the pool math tool to get an initial number and then to test all your water in a 2 gallon bucket as a control test sample, rather than "dump and pray" in your pool which is a big waste of time and chemicals.
I found that my pool actually takes 2x the amount of muriatic and 3x the amount of chlorine to move the needle compared to the pool math calculator.
Note on alkalinity: According to EPA, alkalinity is the water's resistance change to acid. I loaded the alkalinity in my 2 gallon bucket to 300ppm, and reduced the acidity to 7.2ph. Within a fortnight the PH was back above 8.2. My alkalinity in my pool stands at 60-80, and is very consistent when I reduce it to 7.2-7.4ph. My conclusion here is that, if you have an algae problem, to get the maximum effect of chlorine, you would have to lower your alkalinity to maintain a low ph. There's a good corrosion to PH chart that should be referenced to. Although at 60-80 ppm 7.2 ph is technically corrosive (however minor), it is the best way to kill algae, and once that's done, I would probably bring my alkalinity back to 125 and keep my ph at 7.5 (neutral). Tip here is to downloading this graph (available on the net). So tip here is to adjust alkalinity as needed rather than "keep it at ideal alkalinity"
You can also get more use out of the test kit by halving the amount of chemicals used and halving the water amount. (duh right?) Readings by 1ppm is the same as .5, and readings by 20 ppm alkalinity.
That's my tips and findings so far, but more to play.