Fellow Houstonian here. New pool just finished in December. Buy the TF-100 kit now, start testing before the summer gets here. It takes a few trues but you quickly get used to it. Since the pool has been finished, I've only ever had to purchase the following for maintenance:
- Muriatic Acid to lower pH due to new plaster
- HEB Chlorine to raise Free Chlorine (FC) levels when the water was too cold for the SWGC. This will probably go away since the water temp is rising now.
I've had to buy Cyanuric Acid and calcium chloride as part of my start up process (and salt of course), but I haven't had to get more since the start up.
I am a believe of TFP for sure.