OpenSprinkler Forums Pictures and Creative Use Using Open sprinkler to control a peristaltic pump to chlorinate my pool


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    Check this out:

    Its awesome.  I have it set up as zone 9 called Chlorination.  I take a chlorine measurement, then adjust my run time.  It runs each day at 8pm.

    My post on



    Cool. Thanks for sharing. I had to register an account to see the picture. So I am re-posting it here for those who are curious. Hope you don’t mind 🙂



    Its working well and impresses visitors that I can dial up or down my Chlorine. It was also nice to finally fire up the sprinkler system for the first time since I added opensprnkler at my new house. I walked around the yard, turning on zones, then describing them with real world names as I figured out which was which. I love this system.



    SO the chlorinating has been working very well. I had one time this summer where the controller just shut down. I could not connect on my phone, and I had to reset the power to the unit. Otherwise, its been rock solid and I have really been enjoying it.

    Last weekend, I got a helper and dug up an existing valve. I added another valve to my system that will be my pool fill line. I tied it into my waterfall pump discharge piping. I don’t have it wired yet, but I will manually alter the time that the system adds water each day, until I get a good handle on evaporation. It will be interesting to see how the weather data will influence the pool level. I told my wife that it will automatically add water each day (no chance of leaving the hose on overnight) and I told her how it would be neat to have it adjust fill volume with the temperature… and she suggested that the rain might be more important. It’s neat to think that it may work out just by changing a boolean and making the fill program affected by weather adjustment. Awesome that it might be close to correct for little extra work by me.



    cool project. I’ve been toying with some ideas about managing my pool water levels.

    some thoughts:

    1) I presume your pool has an overflow drain, so that excess rainfall will dump water (and chlorine) out of your pool. My pool can only take about a half inch of rainfall before it dumps. So, increasing the height of the overflow and decreasing the normal level of the pool can save water. And holding off filling the pool if the weather predicts rain is another way of saving.

    2) I gave up on liquid chlorine (too harsh on my wife’s skin; the conditioner chemicals making the water hard, smell, and not liking to have harsh chemicals around the yard), and when to a chlorine generator/salt pool system. We love it. The power supply to the salt generator is way over priced, so there is an opportunity for a DIY/open source project to drive a salt cell with a power supply/controller.

    3) I’ve saved a ton of money by running my pool filter pump at lower speed for a longer time, and shifting the filtration cycle to lower time-of-use rates. Smarter control of the pool speed can really help. Pentair variable speed pumps have a digital interface gadget that you turn on the pump at four different speeds with 4 different 24AC signals. So an AC OS board could control the pump without messing with 220V wiring. They can also be controlled with an RS 485 protocol, but this would require some reverse engineering to figure out their codes.

    So, the OS hardware is very close to what’s needed to manage a pool system 🙂

    I’m interested to hear how you progress.



    Mine is an inground pool with NO overflow. If the water gets too high, it just runs over the flagstone coping and runs off into the yard, which I prefer anyways, VS sending perfectly fine water down the drain to the sewer. I am OK with no overflow.

    My brother in law had a saltwater pool for a few years and found that it really was hard on his stonework and his pool furniture. He now chlorinates again and swears that he less wear on his stone and his aluminum pool area furniture. I am just fine with the Chlorine setup that I have now. Its really easy and automatic with the opensprinkler controlling my chrloination.

    Now, for the fill…I am going to gather some data. I picked a place inside my skimmer yesterday, and made a mark with a sharpie. If I run my tape measure down to the top of the skimmer housing, I can measure the depth at the same place each time. I plan to make a table in a few days, that will record the pool depth and also some weather parameters. I thought about recording the high temp, whether its sunny or windy… But a simpler way may be to record the weather adjustment that is offered up by opensprinkler for that day. I have not yet paid much attention to that side of things, but it would be handiest to arrive at a correlation between the opensprinkler weather adjustment data and the evap rate of the pool. For filling, it will be a simple matter to run the fill valve and see how many minutes it takes to raise the pool 1/4″. That’s the easy part.



    Evaporation is the larger of the results of the following equations

    E0 = 290Dw((Dr-Dw)^(1/3))(Ww-Wr)
    E0 = 0.0346(pw-pr)

    E0 = evaporation from pool, pounds per hour per square foot of exposed surface area
    Dw = density of air saturated at water temperature, pounds per cubic foot of dry air
    Dr = density of air saturated at air temperature, pounds per cubic foot of dry air
    Ww = humidity ratio, air saturated at water temperature, pounds per pound
    Wr = humidity ratio, at air temperature, pounds per pound
    pw = water-vapor pressure in air, air saturated at water temperature, inches of mercury
    pr = water-vapor pressure in air, at air temperature, inches of mercury

    The above I got from somewhere to calculate pool evaporation for indoor pools and adpapted it slightly. If you account for rain filling, it actually works quite well for running a fill system. You will of course have to convert the volume measurements, to run on the sprinkler controller, but that should handle the majority of the ground work. I personally had a dedicated pump controller that used those measurements.

    Hope it helps a bit.



    I know that our pool gets more cloudy after a good rain, and then requires us to use more chlorine. Would be interesting to have the sprinkler controller adjust the amount of chlorine added as a function of how much rain had occurred.



    I had a little bit of trouble with the tubing on my pump (wrong type of connector) but opensprinkler has been rocksolid. I love it.

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OpenSprinkler Forums Pictures and Creative Use Using Open sprinkler to control a peristaltic pump to chlorinate my pool