Bacteria, Giardia and Cryptosporidium: UV vs Filtration

Rat beside a glass – if it goes in your tank, it goes in you (Puretec Hybrid E)

There are two main ways Puretec systems treat microbiological contaminants: Radfire™ ultraviolet (UV), which Puretec states kills up to 99.9% or 99.99% of bacteria depending on the model, including E. coli, Giardia and Cryptosporidium cysts; and ultrafine Ultra Z filtration down to 0.1 micron (nominal), which protects against cysts and bacteria such as E. coli at a single tap. For Cryptosporidium, Puretec says a whole-house system is the primary choice because it treats every tap and the shower.

Why these contaminants matter

Puretec explains that rain, surface and bore water can easily become contaminated, and surface and bore water so easily that bacteria treatment becomes critical. Cryptosporidium is a microscopic parasite protected by an outer shell, which makes it tolerant to chlorine disinfection – so even chlorine-treated mains water can be affected during an outbreak. For health concerns or symptoms, contact your doctor or state health department.

UV treatment (Radfire™)

UV treats water without chemicals. Puretec’s systems filter the water first, then pass it through a UV chamber:

Hybrid E13 and Hybrid E7 – whole-house filtration and UV; Puretec states they kill up to 99.99% of E. coli, Giardia, bacteria and Cryptosporidium cysts. Puretec quotes the E13 at up to 120 Lpm at 40 mJ/cm².
WU-UV150 – an indoor whole-house filtration and UV system for mains or rainwater.
Hybrid M1 – under-sink filtration and UV for one tap, killing up to 99.9% of bacteria; up to 8 Lpm at 30 mJ/cm², which Puretec describes as the industry standard dose for drinking water.

Ultrafine filtration (Ultra Z)

The PureMix Z6 filters down to 0.1 micron (nominal), including Giardia and Cryptosporidium cysts, and protects against bacteria such as E. coli, at up to 9.5 Lpm. Puretec’s Z1-R cartridge, used in Z1 systems at up to 5.5 Lpm, is rated for 99.9% reduction of Giardia and Cryptosporidium cysts.

Whole house or single tap?

Puretec notes that point-of-use systems have excellent filtration capacity but protect only one point of use. For Cryptosporidium treatment you would need a system for each household tap, it would not protect shower water, and cross-contamination between hot and cold lines needs to be considered. Because the parasite can survive outside the body, Puretec stresses treating all water used in the home – drinking, food preparation, showering and brushing teeth.

Limits to keep in mind

UV treatment assumes the water remains clear and flow rates do not exceed the maximum at the specified UV dose.
Iron prevents UV sterilisation from working, so bore water with iron needs treating first.
For surface or bore water, Puretec requires a water test before purchase.
Maintenance: Puretec says Hybrid E maintenance includes replacing the UV lamp once a year and periodically cleaning the sleeve.

Installation: connection to your water supply must be carried out by a licensed plumber, and any hard-wired electrical work by a licensed electrician.

Frequently asked questions

Does chlorine in mains water kill Cryptosporidium?

Puretec explains that Cryptosporidium is protected by an outer shell that makes it tolerant to chlorine disinfection, which is why outbreaks can occur even in chlorine-treated mains water.

Is UV enough on its own?

Puretec’s UV systems filter the water first, because UV treatment assumes the water remains clear and flow rates stay within the maximum at the specified UV dose. Iron also stops UV from working properly.

Can an under-sink filter protect my whole house?

No. Puretec notes point-of-use systems protect a single tap only and do not protect shower water. A whole-house system is its primary choice for Cryptosporidium.