We also live in Houston and have had two different reputable companies tell us to stay away from SWG (both have been in business over 20 years). They said they have clients that are now switching back...apparently it etches into coping, decks, etc. and wears out patio furniture. One pool company suggested chlorine with an ozonator so we would need less chlorine. I am interested in any feedback from someone who has either system and any experience with this.