For Houston - your swim seasons will be longer than most of the rest of the country, and you will never really close the pool. The tab chlorinator will quickly mess up other chemicals (esp CYA) over time leading to a cycle of drain and fill and drain and fill over the life. The SWG will produce chlorine only on a continuous basis (as long as the pump is running) until the water temp is about 60 deg then you really won't need a lot of chlorine and can use liquid chlorine until the temp comes back.
You will have intense UV (speaking from experience in Houston). I have a IC40 (a 40k gallon rated SWG) on my 10k pool, and in the heat of Houston summer this year was running 30% with a pump that runs 24/7, even with high CYA. You will need 4-5ppm per day of chlorine in summer peak, even with a high CYA.
Other reasons for SWG:
- can go on vacation easily
- delivers chlorine continuously (see pump comment) so not having a spike and fall and spike and fall
- doesn't mess up CYA or CH (if using trichlor or dichlor tabs)
- dont have to lug jugs or pounds of tabs
- etc.
If you have a variable speed pump, get a larger one. The larger the pump, the more efficient you can run at low speeds (more water at less rpm, comparatively) and save a LOT on electricity. I run my 3hp VS pump 24/7 for about 15-20$ a month, as it uses 74 watts at my "minimum SWG flow" rpm (1000 rpm). At medium speed (2400 rpm) it uses 1200 watts. Hence, the electricity used is not linear but exponential for pumps and speed.
Marry a SWG at least 2x your pool (hopefully 3x - I would go for one of the 60k gallon rated ones), a larger VS pump, and a large filter, and you have a very nice pool setup. Add automation (and make sure they all work together) and you have very fine control of the pool.
see
SWG How It Works - Further Reading
