I am building a swimming pool Ionizer.

I am using a PIC12F200 to switch a relay on for one hour then off for one hour.

The relay is a double pole double toggle wired to switch the electrodes between positive and negative.

The electrodes are basically two copper strips.


The power source is a 6Volt 0.3Watt panel so will only have a maximum current of 50mA.

What I am trying to find out is if I need a resistor on the electrode.

 

Probably not, but try it! If the water is so conductive that it lowers your voltage so far that there is not enough left for the PIC, add a resistor.

 

I dont know what such a small electrical current through the water is supposed to do to your pool, but my hot tub has an ozonator to kill bacteria instead of using chlorine. it is a box with an ultraviolet light that air is pulled through which then bubbles through the water to kill germs and bacteria. the ultraviolet ionizes the air to produce ozone.

 

I dont know what such a small electrical current through the water is supposed to do to your pool....

It's supposed to add copper ions to the water, which are toxic to a few microorganisms.

 

wouldnt silver be better for this? it is toxic to a lot of microorganisms.

 

It is used, but it's also more expensive. I think the normal commercial devices for this are mostly copper. Staining might be an issue. The copper is a problem in this regard (blondes can get green hair from swimming in your pool!), I'm not sure about silver.

I got curious and studied why copper is so widely used in breweries. I though it might help with controlling undesired fermentation organisms. Nope, it's more about traditional metallurgy. Highly heat conductivity, easily shaped and joined, and more-or-less inert in the beer process. Until recently, it was less expensive than stainless.

It's not entirely inert - it helps catalyze the removal of hydrogen sulfide created by the fermentation. If you're not using a copper pot, you can add a copper penny to accomplish this.

 

Is it necessary to have the probes oscillating between positive and negative. I was considering the oscillations to be every hour. I am really stabbing in the dark here. I watched a you tube video where a panel was connected to two copper probes to a solar panel put it into the water and claims it works. I assume that by monitoring the pool PH will be an indication if the unit is working.

 

I think the pool pH will be unaffected by this, unless you mean that an infection will change the pH.

The change in polarity is though to prevent fouling of the copper probes. I doubt that it needs to happen very often. You could probably even switch them manually once a day or so and not see much difference. But I'm guessing, and don't have firsthand knowledge of these things. I just know the current level is so low that I doubt anything much is happening quickly.

 

also the reversing is to prevent one electrode from platng to the other.