Scott, with all due respect to your intent to keep things simple, I have to take exception with some of the absolutes you have stated. We have many plaster (limestone/calcium carbonate) pools that have lasted in excess of 20 years and started installing Diamond Brite when it first came out in 1992 without any failures I know of to date. At that time it was about 3% quartz, 3% ceramic coated silica and the rest was limestone. The main difference was it came in premixed bags which kept the plaster crew from weakening the cement/aggregate ratio. When exposed aggregate finishes(pebbletech)became available in our area (1999), we tried it on a pool and it has also held up fine with exception to some pebbles coming up. When our plasterer became the authorized Pebbletech installer 4 years ago we started offering it as a finish and have been satisfied. Keep in mind that it, like plaster or quartz are all bonded together with portland cement which is primarily made with finely ground, dehydrated calcium carbonate or limestone. Travertine is very pourous limestone which allows it to absorb a higher % of water and air making it susceptable to expansion of drying salt crystals and freeze damage. That feature also allows it to be the coolest surface availble and very similar to kool-deck which is limestone or the same material used when plastering a pool with a richer cement/aggregate ratio and an application process that promotes porosity. All limestone is not the same density and travertine could mean minimal channelling or it could be extremely pourous. Limestone can also be as dense as 8000 psi. The denser limestone is the prefered choice for what is commonly referred to as marble. Although I haven't seen many tops of salt shakers rust because they are probably made of very noble metals, I have seen many cars, boat trailers and their wiring, boats and fishing reels rust beyond repair if the salt is not rinsed off immediately with fresh water. Boats have sacrificial anodes which minimize corrosion when they are immersed in an electrolyte (salty or polluted water)but have no impact on the post corrosion after the boat is removed from the water. In our area it takes 7+ years for a pool with a strong southern exposure to build up enough CYA before it needs to be drained from using trichlor as the primary sanitizer. Some pools never reach that level. We get about 4 feet of annual rainfall per year which might dilute them more than average and we often supplement the spas with ozonators. In summary there are lots of applications that work for different conditions and applying the same set of rules to all conditions isn't always the best method.

Also be sure your pool is properly bonded. The cell gets installed after the heater. A 35 to 40,000 gallon pool dictates a cell sized for up to 60,000 gallons which means either the Pentair or Auto Pilot. As said earlier, both are fine units. The Pentair is easier to winterize since it doesn't require a manifold like the Auto Pilot. The reason for going slightly over sized is to leave some chlorine generating head room for high temps and heavy usage. More cell plate surface area can help some in the longevity of the cell's life. That's not to say if they made a cell for a 100K gallon pool (no one makes a single cell for residential pools that big, btw) would be beneficial as it would be difficult to control the output to the needed level. Going one size up, I have found, works well and is cost effective. There is no conversion. It's still a chlorine pool. The difference is simply how the chlorine is getting in the pool and byproducts. It will change the way your pH is kept in check. 3" tabs tend to cause the pH to drop and the stabilizer to increase. Cal-Hypo adds calcium. Salt cells tend to raise the pH. Check the salt cells and BBB sections at troublefreepools.com to be be prepared and see how to spend less at the pool store for chems. Scott Scott

The circuit board in our salt generator control box went bad after about two years. It had a 3-year warranty, so it was no big deal, except that it took me weeks and weeks to figure out that something was wrong. We had had a lot of rain, and I kept blaming it on the water just getting too diluted. I cleaned the salt cells. I tried to reset the box. Etc. Finally I did something and got an error message (I think, or maybe I'm confusing it with the spa heater, whose circuit board has been replaced twice due to rats chewing on it). and I finally realized that it really wasn't working.

Just intalled a salt system with that unit. So far so good. The user's guide has a procedure for manual cleaning of IECG blades and I would recommend trying that to get rid of build up. Are you sure your stone is natural and not manufactured stone? I use to sell stone products on the side and though nobody ever told me, I KNEW not to use manufactured stone around a pool. It is a lightweight concrete and is essentially decorative in nature. Salt and chlorine is going to eat it up eventually. Natural stone is MUCH denser and should last longer, but no doubt different types of stone have diffferent chemical makeups, some which will react with NaCL (salt)