Advice on new pool build

[mdemers]

First of all, this is a great site. I have browsed it extensively, but this is my first post.

I am about to go under contract to build an 18x42 gunite IG. I am doing a pure rectangle, as I am using an automatic safety cover. We will also be using solar. I am down to deciding between two PBs. I live in Gilroy, CA.

I need to make a few decisions and I would appreciate some advice:

Jandy Ray-Vac vs Polaris 280: I am leaning towards the Jandy as I would like to avoid the booster pump. With an autocover, that will be closed except when we are in the pool, and no substantial trees near the pool (this is a new house and there is no landscaping yet, so I can control all of that) I expect a reasonably light debris load. I have heard that the Ray-Vac can tend to get stuck in the corners of a rectangular pool.
(BTW, none of the pool builders here seem to be aware of the robotics.).

Pebble-Tec vs 3M Quartz: Does anyone have an opinion on the relative durability of these two?

SWCG vs Ozone+mineral treatment: I am clear about the benefits of a SWCG from reading this site. I also heard the doubts about ozone and the mineral based treatments. One of the builders installs 95% of his recent pools (over 200 pools total) with Ultrapure Ozone (UV type) and Pool Rx mineral treatment backed up by a Rainbow 320 injector. They only do SWCG when the client insists. I saw maybe 6-7 pools, in service, and they all had pristine water appearance. Granted, it is not swim season yet, but the homeowners had very positive comments on water quality and ease of maintenance. Also the salesman could not tell me what the chlorine levels were. He did have concerns about salt corrosion of decking, and I have seen some comments on that here also. I was leaning towards SWCG, based on the comments on this site, now I am up on the fence. I have also seen Ben’s warnings in Tip #2 about not using grocery store chemicals with silver/copper systems, but I don’t understand them.

Pumps: I really want to keep energy use down. All the pool builders here just use single speed pumps (even though Title 20 goes into effect in January where 2-speeds will be mandated by Californian law, they seem to be oblivious) I am insisting on a two speed. One builder uses the Jandy Stealth, one uses the Hayward Northstar. I like the concept of the 4x160 intelliflow. Will I really save enough energy over a two speed to press the PB to support me on this? Both PBs are recommending the Jandy controllers, so I am not likely to go the full route of the variable speed intelliflow with Intellitouch. I read recently, that Pentair was going to update their web-site to say the energy savings between the two Inelliflows was comparable, so precise flow control is the only reason to go to the latter set-up. Will I have issues having the Jandy control the 4x160?

Finally, we are trying to decide between a spa built into a corner of the pool, under the cover, vs a standalone/portable spa. The portables have much, much greater functionality, but have separate maintenance and longevity issues. Has anyone else faced this decision?

[chem geek]

For the full Intelliflow vs. 4x160 decision, they do not have the same cost savings unless your situation is such where all of your programmed features have a fixed and known amount of time. In that case, you can try and figure out one turnover of water per day spread out over time in the most economical way and that will be the same for both pumps. If you have no features at all and only need one pump speed, then the 4x160 will do just fine.

However, if you have any sort of dynamic feature situation, such as a solar system that requires higher GPM (and it sounds like you do), then the full IntelliFlow will usually be more economical since it will turn off the pump when a full turnover has been reached (assuming the "feature" is off -- i.e. that you don't need further solar heating). With the 4x160, the pump doesn't keep track of the fact that the high GPM feature has met your turnover requirement so after the feature turns off it keeps running at the low GPM rate (you can only set the RPM and have to guess or figure out from pump charts what the GPM is).

The full Intelliflow will also ensure that the GPM is maintained, and therefore a full turnover is achieved, even when your filter gets dirty. The 4x160 is more likely to have its GPM rate slow down as the filter gets dirty (since its RPM is what remains constant) so you could end up with less than a full turnover of water and have to adjust for that manually by monitoring your filter pressure and doing the calculations. Of course, this difference in GPM may not be very big so is probably not something to worry about.

The Rainbow 320 injector is used to inject chlorine (typically dissolving Trichlor tabs) into the water, so is that something the pool builder always has operating? I wasn't clear if "backed by" meant "augmented" or "used in conjunction with" or if it meant "backed up in case of failure?". An ozone or mineral or combination system still requires chlorine in the pool, though the amount can generally be lower (this is also true for an SWG where the chlorine level is typically lower than in a non-SWG pool). Since you have to have some chlorine anyway, I'm not clear on the benefits the pool builder sees from having an ozone system plus minerals in the water when chlorine alone will work well. In fact, if you put in a peristaltic pump feeder to inject chlorinating liquid or bleach, then you'd have an automated system that could use chlorine alone and not face the buildup of CYA that normally occurs with use of Trichlor tablets.

[EDIT] In my own pool I have an electric opaque pool cover that is kept closed unless the pool is in use and this makes the chlorine consumption very low, about 0.5 ppm FC per day in a 16,000 gallon pool. I usually only have to add chlorine twice a week because of this. I expect that you will see similar low consumpation due to your cover, though your pool may be 1.5x larger so might have 0.75 ppm FC per day consumption. [END-EDIT]

Richard

[mdemers]

Chem Geek,

Thanks for the reply. I do appeciate it when the knowledgeable members of this board take their valuable time to reply. I have not made my final decisions, but your input was very helpful,

thx,
MKD

[CanuckPool]

The only thing I would be concerned when you are getting an SWG pool is that all your stainless screws are of the best quality. The screws that hold my lights in started to rust only 2 months after installation.