Run time percentages and cell life question

[wayner]

FYI - if it makes a difference to any of this I have a Jandy Aquapure 1400 SWCG.

Is the controller for the SWCG smart enough to know when your pool pump is running and adjust for this? (I am guessing no even though it does have a flow sensor).

What I mean by this is that if you have your SWCG set to 50% and your pool only runs 12 hours per day is the system smart enough to run the cell 100% of the time since your pump is running only 12 hours per day?

If I am correct in assuming that it doesn't adjust for this that means that if you have your SWCG set at 50% and your pump runs for 12 hours per day then you are generating Cl for 6 hours per day. So the less that your pool pump runs the higher setting you need on your SWCG.

Will this shorten the life of your salt cell? Let's say you only run your pool pump for 6 hours per day and you have to set your SWCG at 100% to have enough FC. Is that worse for the cell that running your pump 24 hours per day with the SWCG at 25% - in the latter case your cell will be cycling on and off and likely won't run for that long continuously.

 

[JoyfulNoise]

The answer to question is no they are not smart enough. If you add an automation system on to your equipment pad, you can program different pump and SWG cycles but most SWG's do not communicate with the automation system, they are slaved to it.

For an SWG pool, you tend to adjust the cell a few times per season in terms of output % as the temperature and daylight hours change. During the winter, I turn my pump run times down to as low as 2-3 hours per day and my SWG % output down to 20%-25% and that is more than enough to maintain the proper FC. Then, when the hot summer months hit, my pump run times go up to 8 hrs/day and my SWG is up at 50% or more.

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Also, SWG's have finite lifetimes typically defined in how many hours of run time they have (usually around 10,000 hours or so). That's it, that's all you get. So, if you want to extend the life of your cell for as long as possible, you try to find the right water chemistry (higher CYA) and run times that utilize the cell for the least amount of ON time.

Average cell life is 3-5 years. You just assume that going into the game and plan for it.

 

[wayner]

Thanks - I was aware of the cell life as I have already replaced my cell twice - the second change was painful as Jandy changed the union sizes. It is too bad that they can't make all of this equipment intelligent enough that it can communicate with each other.

 

[JoyfulNoise]

Thanks - I was aware of the cell life as I have already replaced my cell twice - the second change was painful as Jandy changed the union sizes. It is too bad that they can't make all of this equipment intelligent enough that it can communicate with each other.

Unfortunately, that would probably drive up the cost of the cell significantly and then make them a less attractive chlorination option. I don't find that I do that many adjustments on my pump run time and cell output that it would really make sense to have a comm link between the pump and SWG.

Now there are automation systems (ORP) that do control the SWG based on feedback. Basically the ORP control activates the SWG (usually at 100% output) when it senses low oxidation potential. Of course, if you read enough here on TFP, you'll quickly realize that ORP is not at all a reliable automation method for outdoor, residential pools. One could use a more reliable amperometric probe to automate the system, but those typically cost thousands of dollars and so don't make much financial sense in a residential setting.

I'm curious, being in Canada, how long does you cell last? The swim season must be shorter and temperatures cooler, I would expect a cell to last longer.

 

[ping]

As Matt stated the lifespan of the cell is roughly 10,000 hours of on time for a lot of SWG cells. It will not make a difference if it is set to 100% or 50%, as turning it off and on will not degrade the cell. If you have the cell set to 50% then the pump run time has to be twice as long if the cell was set to 100%.

If electricity cost is high then we suggest to run the SWG on a high % to shorten the pump run time. With your large pool size, I would find a pump run time that lets the SWG make enough chlorine for your pool with the output set at 80% or higher. I calculated that your SWG can add about 5.7 ppm of FC in a day when it is running all day and set to 100%.

 

[wayner]

I'm curious, being in Canada, how long does you cell last? The swim season must be shorter and temperatures cooler, I would expect a cell to last longer.

My pool is open for roughly five months per year. My first cell lasted about 5-6 years. My second cell was bought from a guy who works on pool systems - it was slightly used but it had the advantage of being a newer cell from Jandy with the old size unions so it didn't require plumbing. That cell lasted only 2-3 years so I wonder how old it was when it was installed and/or whether there were other problems.

My current cell was bought last year but wasn't installed until the start of this pool season due to the plumbing changes required. I put in the new cell but used the old power cord and something was wrong with that cord as it quickly corroded one of the three pins that are attached. So I changed to the new power card but I have had to jerry-rig a connection to keep that working. So we will see how long this one lasts - I should label it so I can easily keep track of this.

 

[wayner]

If electricity cost is high then we suggest to run the SWG on a high % to shorten the pump run time. With your large pool size, I would find a pump run time that lets the SWG make enough chlorine for your pool with the output set at 80% or higher. I calculated that your SWG can add about 5.7 ppm of FC in a day when it is running all day and set to 100%.

My other factor is that I have an evacuated tube solar heating system. So I coordinate the timing of the pump with the hours that the sun is up. That means I do use more expensive electricity during the day (in Ontario it is $.08 more during peak vs off-peak) but I spend much less on NatGas to keep the pool in the mid 80s.

 

[wayner]

Unfortunately, that would probably drive up the cost of the cell significantly and then make them a less attractive chlorination option. I don't find that I do that many adjustments on my pump run time and cell output that it would really make sense to have a comm link between the pump and SWG.

[rant]One of the things that I really find annoying about pool equipment is that it is so expensive to add automation and/or have "smart" devices. Hardware is really cheap these days and putting IP connectivity on all devices can't cost very much at all. Then you could have APIs so that everything could be automated. The actual hardware costs aren't that high, but some of the software might cost a bit, but I am guessing that you could reuse software written for other purposes, like smart irrigation controllers, Nest thermostats, etc. Heck, you could just throw a Raspberry Pi in every device - SWCG controller, pool heater, etc and the hardware costs is $30. Then just make sure that the Pi can read all sensors, etc and automation would be easy[/rant]

I am a bit of a computer geek and where possible I buy smart devices - like my IrrigationCaddy irrigation controller, Hue lighting, Control4 Home Automation system, iGrill2 bbq thermometer, etc. But the pool equipment manufacturers are years behind on this stuff. Maybe the reason is that pool equipment doesn't have economies of scale, but I doubt that.

 

[JoyfulNoise]

[rant]One of the things that I really find annoying about pool equipment is that it is so expensive to add automation and/or have "smart" devices. Hardware is really cheap these days and putting IP connectivity on all devices can't cost very much at all. Then you could have APIs so that everything could be automated. The actual hardware costs aren't that high, but some of the software might cost a bit, but I am guessing that you could reuse software written for other purposes, like smart irrigation controllers, Nest thermostats, etc. Heck, you could just throw a Raspberry Pi in every device - SWCG controller, pool heater, etc and the hardware costs is $30. Then just make sure that the Pi can read all sensors, etc and automation would be easy[/rant]

I am a bit of a computer geek and where possible I buy smart devices - like my IrrigationCaddy irrigation controller, Hue lighting, Control4 Home Automation system, iGrill2 bbq thermometer, etc. But the pool equipment manufacturers are years behind on this stuff. Maybe the reason is that pool equipment doesn't have economies of scale, but I doubt that.

I get that as I am engineer who has built his fair share of automated lab equipment. The level of automation available nowadays to the consumer is incredible but the interest level in the general market is limited. Herein lies your problem - while you and I and folks like us are interested in this stuff, we are, as an old colleague of mine use to say, NOT normal. You, me and engineer/nerds like us are several sigmas away from the peak of the Bell Curve. Given that most pool owners just want a tub of water with a pump and a filter that stays clean for a few months out of the year, the market forces drive equipment makers to the cheapest and simplest systems to sell.

You also have to realize that it is not just putting an ethernet plug on a piece of equipment. There's all the programming and circuitry needed to make it work and that has to be built for outdoor use (MIL spec would be nice, but a bit overkill). Then there's all the service techs and sales people that need to be trained on it and able to answer the questions when the 79-year old grandmother of 12 who is freaking out on the phone because her 12 grandkids can't swim because this dag-blasted piece of whiz-bang technology just flashes red lights at her....

But hey, if you like playing with Raspberry Pi's and programming, feel free to automate the heck out of your equipment pad and sends us all some pics

 

[wayner]

I am an electrical engineer but I haven't actually done engineering work as a job for over 20 years.

I think the general interest in this stuff is growing and that is why that Apple, Google, etc are getting into Home Automation. Products like the Nest thermostat show that consumers do have some interest in this stuff. I think it would be useful to everyone to have remote control of their pool controls. For example, being able to turn on your heater from your smartphone when you aren't home can be very useful.

The other factor that could push automation is resources (like water) becoming more scarce and therefore expensive. Smart irrigation systems can adjust the amount of water thrown on your lawn/garden based on past rainfall, expected rainfall, temperature, sunlight, wind, etc. As water prices go up that makes more economic sense. Similarly for pools, you could probably come up with a good equation that explains FC loss due to sunlight, temperature, etc and crank your SWCG up or down based on that. Of course, being able to electronically read FC on an economic basis would be of huge benefit to the pool service industry.

By the way my summer electronics project was called PoolPi. It is a Raspberry Pi in a floating plastic container powered by solar panels and batteries. It has a temperature sensor to read water temps and I was thinking of adding on sensors for pH and ORP. I was also thinking of adding in motion sensors so it can alert me that someone is likely in the pool. But I ran out of time and energy to do most of this.

But it is hard to have a DIY project here unless I can get readings out of my pool heater and SWCG and if I can easily control the levels of parameters like heater target temp, SWCG level, etc. That is where they could make it easy for us at low cost. Add some type of interface, be it IP, RS-232, i2C, OneWire, etc. You can't do much without that. The easiest and cheapest way to do this today might be to monitor it with a camera and OCR the image file which is kind of sad.

There is an OpenSource project called OpenSprinkler, and OpenSprinkler Pi. These allow you to use your Pi as an irrigation controller. Some of this functionality, like tripping relays on a timer and having weatherproof casing, could be adapted to pools. But you still need to get data from your pool equipment to the Pi.

 

[chiefwej]

To the life of the cell and amount of chlorine produced running a SWG at 25% for 24 hrs, 50% for 12 hr, 100% for 6hrs are all exactly the same. The cell when it is producing is always running at 100%. Reducing the control to say 30% causes the unit to cycle between on and off, with the cell being on only 30% of the time.

 

[peterl1365]

I am an electrical engineer but I haven't actually done engineering work as a job for over 20 years.

I think the general interest in this stuff is growing and that is why that Apple, Google, etc are getting into Home Automation. Products like the Nest thermostat show that consumers do have some interest in this stuff. I think it would be useful to everyone to have remote control of their pool controls. For example, being able to turn on your heater from your smartphone when you aren't home can be very useful.

The other factor that could push automation is resources (like water) becoming more scarce and therefore expensive. Smart irrigation systems can adjust the amount of water thrown on your lawn/garden based on past rainfall, expected rainfall, temperature, sunlight, wind, etc. As water prices go up that makes more economic sense. Similarly for pools, you could probably come up with a good equation that explains FC loss due to sunlight, temperature, etc and crank your SWCG up or down based on that. Of course, being able to electronically read FC on an economic basis would be of huge benefit to the pool service industry.

By the way my summer electronics project was called PoolPi. It is a Raspberry Pi in a floating plastic container powered by solar panels and batteries. It has a temperature sensor to read water temps and I was thinking of adding on sensors for pH and ORP. I was also thinking of adding in motion sensors so it can alert me that someone is likely in the pool. But I ran out of time and energy to do most of this.

But it is hard to have a DIY project here unless I can get readings out of my pool heater and SWCG and if I can easily control the levels of parameters like heater target temp, SWCG level, etc. That is where they could make it easy for us at low cost. Add some type of interface, be it IP, RS-232, i2C, OneWire, etc. You can't do much without that. The easiest and cheapest way to do this today might be to monitor it with a camera and OCR the image file which is kind of sad.

There is an OpenSource project called OpenSprinkler, and OpenSprinkler Pi. These allow you to use your Pi as an irrigation controller. Some of this functionality, like tripping relays on a timer and having weatherproof casing, could be adapted to pools. But you still need to get data from your pool equipment to the Pi.

I think the biggest problem is that the pool automation systems don't have any reliable sensors. I tried to do some home-brewed automation 8 years ago when our pool was built, but the cost of getting the necessary measurements (pH, CL, hardness, etc) into the system made it an unattractive project.

Besides that, the equipment companies want you to buy their overpriced control solutions (and there's probably a liability issue as well). FWIW, my Pentair system can communicate with devices via RS-485, but I don't think Pentair has ever released their communications protocol, which makes it generally useless for third-party automation.

Perhaps the next generation of controllers will have wifi and built-in web servers for configuration and diagnostics, but I wouldn't hold my breath. I think the pool service industry is pretty much where auto mechanics were 25 years ago before the widespread use of onboard diagnostics and computers.

 

[wayner]

I know that sensors for CL, pH, etc aren't available for a cheap price but I would at least like the following:
Web read access for everything on my SWCG screen (temp, salinity, service code)
Ability to set SWCG percentage or turn off or to 24 hour shock.
Ability to control pump from web UI, including complex timer (more than one off and one on setting per day)
Ability to control heater from web UI and also do heater scheduling by time of day and day of week - once the kids are back in school in September I often don't hear the pool during the week.

These asks are not rocket science, they just require an interface to a few devices.

 

[RustyFN]

To the life of the cell and amount of chlorine produced running a SWG at 25% for 24 hrs, 50% for 12 hr, 100% for 6hrs are all exactly the same. The cell when it is producing is always running at 100%. Reducing the control to say 30% causes the unit to cycle between on and off, with the cell being on only 30% of the time.

Thanks that helped me a lot. I am just getting started with a SWG and am running at 20%.

 

[peterl1365]

I know that sensors for CL, pH, etc aren't available for a cheap price but I would at least like the following:
Web read access for everything on my SWCG screen (temp, salinity, service code)
Ability to set SWCG percentage or turn off or to 24 hour shock.
Ability to control pump from web UI, including complex timer (more than one off and one on setting per day)
Ability to control heater from web UI and also do heater scheduling by time of day and day of week - once the kids are back in school in September I often don't hear the pool during the week.

These asks are not rocket science, they just require an interface to a few devices.

This could probably be done without too much trouble (if you have sufficient programming skills), if you could get your hands on the protocol. A simple USB-to-RS485 converter and some code should be all you would need.

I haven't looked into this for some time, so I did a search. Have you considered a canned solution from Pentair.

http://www.pentairpool.com/products/automation-screenlogic2-interface-for-intellitouch-and-easytouch-automation-systems-418.htm

You might also find this interesting:
https://carlstrom.com/pool/compool/

 

[bdavis466]

I know that sensors for CL, pH, etc aren't available for a cheap price but I would at least like the following:
Web read access for everything on my SWCG screen (temp, salinity, service code)
Ability to set SWCG percentage or turn off or to 24 hour shock.
Ability to control pump from web UI, including complex timer (more than one off and one on setting per day)
Ability to control heater from web UI and also do heater scheduling by time of day and day of week - once the kids are back in school in September I often don't hear the pool during the week.

These asks are not rocket science, they just require an interface to a few devices.

Pentair Easytouch with Screenlogic can handle all of that... With that said, the programing is a little clumsy but capable of everything you mentioned.

I'd love to see a system with an actual chlorine sensor instead of using ORP. I guess the cost of the sensor is the limiting factor though.

 

[JoyfulNoise]

Pentair Easytouch with Screenlogic can handle all of that... With that said, the programing is a little clumsy but capable of everything you mentioned.

I'd love to see a system with an actual chlorine sensor instead of using ORP. I guess the cost of the sensor is the limiting factor though.

The only "chlorine" (hypochlorous acid) sensors available are what are called amperometric sensors that measure the current induced by the electrochemical conversion of a Ag metal electrode to silver chloride. The systems typically cost thousands of dollars, the probes are consumable & expensive and are thus limited to mainly large commercial water systems. Few residential pool owners could justify the cost of those sensors.

As for programming interfaces, this is an age-old problem that technologically immature industries suffer from when the individual companies do not adopt a general industry-wide standard. Robust, programmable interfaces will only exist once the Pentair's and Haywards and Jandy's of the pool industry world get together, form a working group and decide to adopt certain standards. Until then, it will always be ad-hoc systems that are specific to each company and have no cross compatibility. Right now, the economic incentives are aligned such that each company would rather develop their own proprietary systems leaving the consumer with few options other than what canned systems each company sells.


Sent from my iPhone using Tapatalk

 

[chiefwej]

It seems that few things are standardized and everything is more expensive, when it comes to the swimming pool market. Pools are a luxury leisure market, not a mainstream consumer market, so few things are standardized and everything cost more.

Limited production, limited demand, leads to limited innovation and high prices. Any consumer product will always be much cheaper than a similar pool product. That's one reason why this forum thrives.