Noob question. How often do you use the FAS/DPD test kit? It would seem that DPD powder would have to be replenished 2 or 3 times a season or more if you used it every other day. Just curious as I've just gotten the test. I guess in my thinking, in "normal" times I would use the OTO kit and for "special" times the FAS/DPD. I happen to be in a "special" time (my pool has issues). It would seem to me at least, that I would want to know exactly what my chlorine levels are, and therefor use the FAS/DPD daily or at least every other day. How else would you know to monitor your levels with the pool calculator?