Combined UV-C and Copper Ionizer

[johnfromen6]

Hi I'm new to the forum and swimming pools and have seen that there is a wealth of experience and help on this forum and was hoping someone might be able to help me with a couple of questions.

Our pool is being constructed at the moment and someone has recommended that we install a Blue Lagoon combined UV-C and Copper Ionizer

I suspect this exact model is not available in the US but if it is and anyone is familiar with it or anything similar I would welcome views but my question is:

It is described as a "chlorine free" solution but somehow I doubt it will be completely free and more likely "low chlorine" i.e. around 0.5 ppm. It has as part of the unit a peristaltic pump to inject liquids in to the pool which can be set to any quantity and time up to 60cc per hour. I realize I would have to monitor it and there are probably other factors that I have not allowed for as I'm new to this but as a starting point if I wanted to use the pump to inject liquid chlorine in to the pool to achieve 0.5 ppm at what quantity per hour would I have to set the pump?

I suspect the flow rate of my main pump will be relevant and I don't know this yet but if there is a formula that I can use when I know it that would be great.

I hope someone can help.

Many thanks

John

 

[JasonLion]

Welcome to TFP!

I don't recommend that system. Copper based systems run the risk of leaving unsightly stains that are very difficult, or sometimes impossible, to remove. Also, without a residual sanitizer in the water there is nothing to prevent person to person transmission of disease.

 

[johnfromen6]

Thanks for the reply JasonLion. We're actually having a black liner installed (odd I know but there is a reason for it to do with the setting that the pool is being built in) so I doubt any staining will be very visible plus the copper release is adjustable and you are supposed to adjust it till you get the copper content to between 0.5 and 0.7 ppm - at these levels I'd be surprised if there is a real risk of staining?

On the person to person infection, this is probably something that shows my inexperience, but if the combination of the UV-C and Copper are supposed to kill 100% of the bacteria and viruses (but to be on the safe side I'm intending to drip feed chlorine too (the quantity and rate being my main question for the forum)) then is there any more risk of person to person infection when bathers get out of the pool than from them hugging each other before they get in (I should have said this is a private family pool not a public one)?

All the best

John

 

[JasonLion]

Copper kills nearly everything, but does so extremely slowly. If someone uses the pool, then copper will have killed everything that came along with them by several days to a week later. UV will kill everything that passes through the pump more or less instantly, but it can take days to a week for all of the water to actually pass through the pump.

There is more risk from water borne transmission than from routine contact. Many bacteria/viruses are not airborne and don't survive well in the relatively dry environment of skin to skin contact, but do just fine in water borne transmission.

Some copper stains are more or less black and won't be obvious on a black pool, but often they are a green color, the same color as buildings with copper roofs turn. Copper stains are likely any time the copper level goes above 0.3 unless you keep tight control over the PH. Copper won't stain at low PH levels, but PH has a habit of drifting up and that can cause problems if you don't pay attention for a few days.

 

[johnfromen6]

I knew I came to the right place thanks for that very clear explanation.

So essentially assuming before going in to the pool the water is bacteria free because the UV at least has been allowed to run long enough for all the water to have passed through it then the risk is from anything that a bather introduces there and then.

Unfortunately I may have to live with that risk (it will be very light use anyway) because I need to avoid a pool with normal levels of chlorine both for allergy reasons and also because the pool is surrounded by a pond with plant life that would die from the chlorine cross-contamination.

So although not ideal I must go for a low chlorine option. Blue lagoon do a UV-C only option with the same peristaltic pump but I again would need to know how to calculate the rate of injection to achieve the low dosage level recommended whatever that might be. Would you know that?

Thanks again for being so patient with a complete newbie.

All the best

John