Swimming pool maintenance

Hi folks,

Due to the lockdown situation we will most probably have to spent our holidays at home. So my wife ordered last week a large swimming pool. Could be setup in a few hours, but daddy has been elected to spent a lot of free time on keeping the water clean...

As a result I would have less time in the evenings for Node-RED developments... Which means it will be a real win-win situation if you guys can help me solving my problem :wink:

I'm a complete noob about water cleaning stuff. But I would like to use Node-RED somehow for helping me to keep my pool clean. So all help is welcome, but please keep in mind that I don't know anything about this topic!!! So please don't use too much expensive words ...

Some things that popup in my head, after reading quickly through some other discussions (which were way above my paygrade):

  • I suppose I need to measure the temperature of the water with some sensor (connected to a Raspberry!)?
  • I need to measure the pH. Is this sensor from @ghayne good enough, and can I wire that easily to a Raspberry? Unfortunately I don't have the knowledge or time to start experimenting with other hardware like Arduino, NodeMCU or whatever :woozy_face: Or are there any other good (and affordable!!) sensors perhaps?
  • Is it doable to not only to measure the ph, but also control it? I see in another discussion that "Automatic pH control is extremely complex" so that is not encouraging. On the other hand found some open source projects like raspipool, but that is for HomeAssistant...
  • Are there any security precautions that I need to take into control? E.g. only control it during the night when nobody is swimming, or send alerts when the values are not safe, or ... I surely don't want to build any stupid things.
  • Others...

And the clock is ticking ...
Damn I thought that a swimming pool would be relaxing. Not :rofl:

Thanks !!!

Here you go Bart. (I cannot follow the link to the electrode)

I know it's not a reef, but the info on pH measurement is OK! :slight_smile:

I found the pH circuit here but you should be able to get it in Holland!


[edit] Or you could just use pH indicator strips :slight_smile:

I'm guessing said pool has a pump?

Altering PH levels of water can be tricky. I don't have first hand experience with it for swimming. But you can possibly get a run away where (say) it is low PH. Stuff is added to up the PH and next thing you know it is too high.

Probably not a good idea to do it in this scenario.

Temperature should be easy to measure.

Good luck! Enjoy it. It is coming on winter here and swimming pools are not exactly popular just now.

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Yes, anything is possible, but for me that would be a definate no, no.
It's one thing to monitor the pH, but getting dosing wrong can have disasterous health consequences, and not worth the risk.
The chemicals involved are very strong.


Oeps. It is now ok.

Thanks for the link!!

Yes I'm afraid so. But would like to have a scientific evidence why it is not possible, with such a great community...

Yes I definately want to avoid that!!! But I can cause the same problems when I do it manually. Definately want to implement monitoring and alarms, even when I control the pH manually!!

I agree with Paul (@Paul-Reed), Monitoring is fine but controlling the pH is just not worth it.
Use indicator strips for monitoring pH and concentrate on getting the chlorine concentration right, which is very important.

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Then there doesn't seem many Node-RED stuff anymore available in this context...

This is what I use

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Also a relatively cheap method, as long as you calibrate! Did it come with buffer solutions?

Please excuse my flat dweller's ignorance but how on earth can a large swimming pool be setup in a few hours? :thinking: (swimming pools aren't very common here in Finland, unsurprisingly)

I have a ready supply of buffer solution (my friend works in a fizzy drinks laboratory!).

It depends how you define large :smile:


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It would be a sight to have this with a Raspberry and sensors hanging from the side... while a grown up man is swimming in it.


Correction: large compared to our previous pool...

After opening the 'large' box, I was quite disappointed: seemed that the wifes from the picture were not included in the package...

I'm very proud that @Paul-Reed has finally admitted that his favorite color is pink. Well done Paul!

I had hoped that somebody said: "hey Bart be careful with controlling the pool, but there us a large mature open-source project available that already..."


12,430L (12.430L for you Bart :slight_smile: ) is a LOT of water! Like I said, use pH strips and put the money you save towards your water costs!

@BartButenaers Dutch/Belgian store Robesol/Koisense (specialising in Koi ponds) have them stocked: https://www.robesol.nl/en/ezo-ph-circuit-87435896.html

Or just use strips :slight_smile:

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Was reading a bit about raspipool, and suddenly I saw this:


Does anybody have an idea which projects they might be talking about?
And does anybody have investigated RaspiPool already, then it would be nice to get some feedback about it... Thanks!!!

Just googled it, have you seen this - https://www.instructables.com/id/Replace-Your-Pool-and-Spa-Controller-With-Raspberr/

Short answer: no. Thanks for the link!

BTW Seems that there are a lot of ph+chlorine controllers on the market for swimming pools, but the prices are ridiculous high for such small pieces of electronic equipments...

The RaspiPool project also looks very promising...
Their hardware diagram seems to contain all sensors that I need (temperature, pH, ORP):

And it is all wired to a Raspberry, just like I want.
Only issue is that it uses HomeAssistant, while I would like to stick to Node-RED...

Would like to order some materials as soon as possible. Does anybody have any remarks or alternatives (e.g. other sensors)?

I am pretty sure you know that, but when ordering a pH probe, take care that it is one which can be constantly in water and also keep in mind that the "cheap" pH probes have a limited life time and like to be in their buffer solutions