Whole house water filter

Forums › Home Workshop DIY › Whole house water filter - for e coli

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MikeAqua

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#3493748 19-May-2026 13:10

tweake:

all the UV systems i've dealt with all run the UV constantly, hence you get a bit of hot water in it if you go away for the weekend. the controller also has built in hour meter as you are meant to replace the lamp after so many hours of use.

That's OK if you can be sure it doesn't run dry. Even then ... maybe that isn't a big deal with LEDs. Leaving a UV filter running 24/7 is a simple way of ensuring it's always ready to go, but it will dramatically shorten its life.

A control panel with an integrated hour meter sounds great - provided it doesn't reset if there's a power outage.

Mike

nutbugs

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#3493767 19-May-2026 14:45

MikeAqua:

A control panel with an integrated hour meter sounds great - provided it doesn't reset if there's a power outage.

The one I use needs a manual reset of hours when you replace the UV element. Definitely holds it's count during power outages.

kingdragonfly

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#3493772 19-May-2026 15:00

I took a look at UV LED system(s); there was only one I could find. The NZ $2,057 AquiSense PearlAqua Deca, without filters.

Pros: consumes electricity only when sterilizing, no warm up, no quart tube to clean and periodically replace. No warm water in fixture while idle.

Cons: not supplied with filters.

From the Youtube video

"The pearl aqua deca is a system that's made to disinfect the water for our whole household so we're talking in excess of 10 gallons per minute."

Not achievable under the physics of this universe, though perhaps entirely routine in a parallel reality where photons lift weights.

UV LEDs produce less than 1 W per module. A mercury lamp produces 10 to 30 W.

A realistic flow rate today for the Deca is 1 to 4 GPM. A low flow very efficient bathroom shower start at 1.5 GPM, and a tap is about 1.5 GPM. It can easily be overrun if more than one fixture is running.

From the AquiSense youtube video

"The pro-aqua deca is a system that has a lower cost of ownership as compared to a traditional mercury system after just three years"

For my calculation because I'll choose the conventional 35 watt bulbs. It's the least capable conventional bulb, even though it exceeds the deca by many times in capability. I guess the power bill is NZ $121/year, and $80 bulb, and $90 quartz tube every three years, and $240 ballast every 5 years, and $600 for UV system one time (no filters).

The PearlAqua Deca will not catch up for at least 30, even under optimistic assumptions. so nowhere close to quoted "3 years"

MikeAqua

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#3493826 19-May-2026 17:08

kingdragonfly: I took a look at UV LED system(s); there was only one I could find. The NZ $2,057 AquiSense PearlAqua Deca, without filters.

Pros: consumes electricity only when sterilizing, no warm up, no quart tube to clean and periodically replace. No warm water in fixture while idle.

Cons: not supplied with filters.

From the Youtube video

"The pearl aqua deca is a system that's made to disinfect the water for our whole household so we're talking in excess of 10 gallons per minute."

Not achievable under the physics of this universe, though perhaps entirely routine in a parallel reality where photons lift weights.

UV LEDs produce less than 1 W per module. A mercury lamp produces 10 to 30 W.

A realistic flow rate today for the Deca is 1 to 4 GPM. A low flow very efficient bathroom shower start at 1.5 GPM, and a tap is about 1.5 GPM. It can easily be overrun if more than one fixture is running.

From the AquiSense youtube video

"The pro-aqua deca is a system that has a lower cost of ownership as compared to a traditional mercury system after just three years"

For my calculation because I'll choose the conventional 35 watt bulbs. It's the least capable conventional bulb, even though it exceeds the deca by many times in capability. I guess the power bill is NZ $121/year, and $80 bulb, and $90 quartz tube every three years, and $240 ballast every 5 years, and $600 for UV system one time (no filters).

The PearlAqua Deca will not catch up for at least 30, even under optimistic assumptions. so nowhere close to quoted "3 years"

If your town supply water is at all decent, it's probably clear enough that you won't need physical filters. They're more for people with roof/creek/bore water.

Watts are misleading. You need to know mJ/cm^2. Those are the UV dose units that matter. I found some info on the deca and the UV dosages look decent. if that info is true, even at 45 lpm you're getting a dose of 16 mJ/cm^2.

10mJ/cm^2 would comfortably give you a 4-log reduction of ecoli. But again, ecoli isn't really the worry. It's just the indicator organism for faecal contamination. For some protozoa, you'd want more like 40mJ/cm^2.

Mike

tweake

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#3493843 19-May-2026 18:02

MikeAqua:

If your town supply water is at all decent, it's probably clear enough that you won't need physical filters. They're more for people with roof/creek/bore water.

i would always filter it regardless. especially if you want to have carbon or other treatments. the filtering side is the cheap part afaik.

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