Hi guys! I'm new here (and to pools in general), but I just wanted to say thanks straight away for all of the very valuable information that you all have provided to me already. I've been lurking on the forum for a couple weeks now just reading and gathering information. I have a couple specific questions about my situation that I hope you will have some input for.
My wife and I are in the process of trying to put an in-ground diving pool (no spa) in our backyard in AZ. It looks like it will be roughly 21,000 gallons when we're done. We're working with 2 different designers currently and are hoping to settle on one soon to get started. I mentioned salt systems to both of the designers and both of them reacted very negatively. One recommended the Frog mineral pack/chlorinator instead and the other recommended just adding chemicals manually as needed. I was kind of surprised about that given how much people here seem to like their saltwater systems. One of the designers went as far as saying that he was going to start making his customers who insist on salt to start signing an "I told you so" waiver. Are these just scare tactics driven by profit motive or should I really be listening? The more I read here, the more I question their motives.
The cons that they mentioned (to the best of my recollection) were the following:
1) We are on ground table water, which is generally very hard water and contains high levels of calcium according to them. They were saying that scaling is going to be a huge problem and we'll be destroying cells in no time. While I buy the high mineral content argument, reading here it seems like scaling is only a problem if you let your pH get out of whack.
2) Splash out onto flagstone erodes the decking. I'm not sure that we'll be going with flagstone either way, but this seems like it could be a valid concern. If it is, then what decking materials would be more resistant to the salt system? I like exposed aggregate concrete, but it may be too hot on the feet to be useful here where summertime temps are generally north of 100 degrees everyday and the sun is very intense.
3) The cells will have to be cleaned with acid and replaced constantly. From reading here, this seems like a false statement if pH is kept in check and you buy a generator that is oversized for the pool so that you don't have to run it at max capacity all the time.
4) You have to add a lot more acid. This does seem to be the case, however, the automatic feeder systems here seem to be a good way to reduce the burden.
5) You have to check pH more often and really stay on top of it. This also seems to be the case, however, it seems like with some of the newer systems this can also be mitigated. I plan to test the pool every week anyway, so I don't see the time factor being a big consideration unless once a week is not enough for salt.
One of the designers actually went as far as saying that they still make plenty of money on SWCGs, indicating that his motives weren't profit driven, however he said something like they'll charge $1400 for a SWCG that only costs them $400. That makes me wonder if they're just using some of the crappiest available generators, which is part of the reason they have not had good experiences with them. If we go the salt route, I was thinking of using the Hayward AquaRite Pro system with sense and dispense driving a peristaltic pump to induce acid for pH control. I would not use the ORP sensing after reading the input of several board members here. Given the location of the pool (direct sun) and intensity of the sun here, it sounds like I'll need to keep stabilizer levels at a ppm that would be too high for ORP sensing to be effective anyway. It seems like this system (rated for pools up to 40k gals) would be large enough to not strain it even in the summers here and would give me a good automatic pH leveler system all for around $2000. I looked at the AutoPilot/PoolPilot products as well, but it seemed that to get exactly what I wanted out of the system it was going to run closer to $4000. What do you guys think? Any personal experiences you'd like to share with this type of setup would be awesome. I read mas's thread about the homemade acid induction system extensively. That system looks great for a homemade/DIY thing, but in this case since everything is going in fresh, I think I'd rather just drop the $200 on a pump and have it controlled by the sense and dispense thing if possible.
My current thinking is that I will probably purchase my own SWCG system and either have them install it or just leave space in the plumbing for it and I will install it later. Are there any pitfalls with this arrangement that I should be aware of (like plumbing lengths, sizes, etc .. things that would make compatibility for adding a SWCG later difficult)? Also, is there any reason that the pH only sense and dispense system wouldn't work well with solar heating? I can't think of why it wouldn't, but I recall reading that when the solar is active, it changes the flow rates and/or run time of the pump or something. We're probably not going to shell out the cash for solar heating when we build the pool, but we'll plumb the stub connections for it and size the pump and things to accommodate one should we decide to add one in the future.