Pool water ionization using copper electrodes

[Luis Pedro]

Hey guys, I've been doing some research on this topic and I would like to ask for your opinion.

I'm wondering if Cu-ETP copper alloy is a good option for pool water treatment using ionization.
The purity of this copper alloy is 99.5%, with the remaining amount being phosphorus and a little bit of oxygen.

I already have an ionization system installed, but now I need to replace the electrodes.
I'm trying to find a better deal by speaking directly with the metal supplier instead of paying over 250 euros for 1.7 kg of copper from the ionization system manufacturer. Which I find very overpriced for 6 copper electrode pieces of 18mm diameter by 100mm long.
As of my research, the most used copper alloys are:

[ul]
[li]85% Cu+15% Zn (brass);[/li]
[li]99.5% pure copper;[/li]
[li]94% Cu + 6% Ag;[/li]
[li]67% Cu + 33% Ag;[/li]
[/ul]

Any advice would be greatly appreciated.

Thanks in advance.

 

[EdStainless]

I would thing that these are pure Cu, or maybe a low silver alloy (as silver is also a disinfectant).
Are all of these rods the same polarity?
Or is this an AC system? (or DC that switches polarity)
The real question is do all of the rods degrade at the same rate?

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P.E. Metallurgy, consulting work welcomed

 

[Luis Pedro]

The ionization system consists of two pairs (+ and -) of three elongated rod electrodes (six in total), disposed in circles with equal spacing and with (+) and (-) polarities.
Electrodes are arranged in a cylindrical cage. Enabling it to work as an electric condenser, where there are periodical DC polarity (24v DC) commutations of current commanded by a time-controlled automatic system.
Because of these polarity commutations, I suppose they all degrade at the same rate (theoretically).

[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1693344051/tips/image_qyrsud.webp[/url]

Also, do you think an increase in the rod diameter from 18mm to 20mm would pose any bummer to the system?

I am inclined to buy the 20mm Cu-ETP copper rod. I don't think the remaining phosphorus and oxygen concentrations will affect efficiency or health.

Thanks in advance

 

[EdStainless]

Depending on their control scheme changing size could change current density.
I wouldn't change.
Polarity switching is how this is commonly handled.
Good to hear.

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P.E. Metallurgy, consulting work welcomed

 

[Luis Pedro]

The original electrode diameter is 18mm.
The metal suppliers I consulted only have either 16mm or 20mm of diameter.
The 16 mm option would be OK, but would mean less electrode life than the previous ones (counts as 2mm were already used).
On the other hand, 20 mm may be too thick and slow down the ionization process because of the current density (as you alerted).

What do you think?

Thanks in advance.

 

[bimr]

I think if you buy one with the same dimensions and weight, it won't make much difference.

People are selling this on ebay cheaply:

ebay

 

[EdStainless]

I was going to say - Go with 20mm but make them shorter so that the surface area is about the same.
How small are the electrodes when you take them out of service?
Are they a lot smaller than when new?
If so then the controls are likely compensating for that and I would just use the 20mm and not worry about it.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed