No problem! I agonized over various RO setups for a while before finally settling on the somewhat mysterious Prime - partly because it seems like an elegant solution and also out of curiosity, since I couldn't find info anywhere from actual users.

The water out tastes quite good, but keep in mind that it has has already passed through my 20" sediment and carbon filters.

I'm not sure it'd be right for your higher chloride level though. With my filter head on position 3, I'm getting a reduction to about 20% of the level going in. If that relationship holds for your chloride of 173 (maybe someone smarter than me, like Pat , could say whether this is a reasonable assumption) you'd be left with an output of 34mg/L, still higher than the La Marzocco max of 30. You might have to set it at position two or even one to get an acceptable low level, with a corresponding reduction in capacity.

Later this week I'll try to make time to test the filter at the various bypass settings to get a better idea of what it's actually doing, esp re chloride. I first need to get a larger test vessel for the fish tank kit...

Splunge wrote:I agonized over various RO setups

Same! While I, like many of us, am somewhere on the OCD spectrum I still aspire to find a low maintenance/low effort and "good enough" solution for my water. (I sometime wish I had not asked about water chemistry )

Splunge wrote:maybe someone smarter than me, like Pat , could say whether this is a reasonable assumption)

This is the one question I am not able to get an answer for... How much reduction in Chlorides should I expect??? I'd be fine with 34 or even around 50... (I am sure that even with Chlorides at 50 I will have plenty of time to enjoy my new machine before it develops issues.)

I called Pentair's tech Support and the rep was not able to give me an accurate answer correlating the input level of Chlorides, the bypass setting and the output level. He just said 87%-90% reduction (but at which setting?)

I am still hopeful that this all-in-one solution can be "good enough" for me: with carbon filtration for taste, elimination of scale and moving Chlorides close to target.

Splunge wrote:Later this week I'll try to make time to test the filter at the various bypass settings to get a better idea of what it's actually doing, esp re chloride.

If you get to do that it'd be amazing.

On a side note - La Marzocco's tech support confirmed that while the specs of the GS/3 call for 2GPM, 1GPM would be enough.

Thanks, Chris (Splunge), for sharing that Claris Prime info. I think you are the first to share info about them here on HB. It's very appreciated.

katkat wrote:This is the one question I am not able to get an answer for... How much reduction in Chlorides should I expect??? I'd be fine with 34 or even around 50... (I am sure that even with Chlorides at 50 I will have plenty of time to enjoy my new machine before it develops issues.)

I think it's reasonable to expect the same fractional result as reported by Splunge -- about 80% reduction at bypass setting 3, or reducing 175 ppm to around 35 ppm. I think I would drop the bypass down to #2 and see how it fared using drop titration kits for chloride, GH, and KH. If you can get average chloride below 30 or so while still keeping average KH above 40 or so I think you can sleep easy about corrosion risks.

katkat wrote:I called Pentair's tech Support and the rep was not able to give me an accurate answer correlating the input level of Chlorides, the bypass setting and the output level. He just said 87%-90% reduction (but at which setting?)

That's really disappointing, but not that surprising. I wonder if there's any way you can convince them to escalate your support to an expert before pulling the trigger on this system? I would hope they have someone there who has technical understanding of this tricky filter and is aware of GS3 water requirements.

I can't say I clearly understand the workings of this filter. It's a little odd to me that you get an increase in filter capacity as the KH of the water goes up. Perhaps the limiting capacity is in the cation resin and is better at higher alkalinity - who knows? This filter is a little is complicated -- doing a few jobs at once with a mix of ion exchange resins and an adjustable bypass.

Splunge wrote:Later this week I'll try to make time to test the filter at the various bypass settings to get a better idea of what it's actually doing, esp re chloride. I first need to get a larger test vessel for the fish tank kit...

That would be great, especially if you have numbers before and after the filter for GH, KH, and chloride ion.

katkat wrote:On a side note - La Marzocco's tech support confirmed that while the specs of the GS/3 call for 2GPM, 1GPM would be enough.

Good to know!



P.S.
Two comments on some earlier calculations:

Splunge wrote:TDS 94 (tds meter)
KH 89.5 (API kit)
GH 89.5 (API kit)
PH 7.2 (Hach strip)
Cl 11 (Hanna drop kit)
With 125ºC water, the online calculator I used gave me a Langelier index of -0.2

Hmm, when I do that calculation I come up with a pHs of 6.3 and at pH = 7.2, the LSI is +0.9. Assuming most or all of that GH is from calcium then I think it's worth looking out for light scale.

katkat wrote:Assuming I'm using the chart on page 11 correctly, my values (KH - 6 drops - 107.4 ppm, GH -11 drops - 196.9 ppm, Chlorides 173) call for bypass 3 and capacity of 530 gallon.

Yes, but if you were to use the values from your water report for the Upper Merion source, you would have a TDS of 588 ppm, chloride of 173, and alkalinity of 214 mg/L (12 °dKH) and reading these on the Claris Prime capacity chart would put you at only 260 gallons at bypass 3 and 210 gallons at bypass 1.

homeburrero wrote: Hmm, when I do that calculation I come up with a pHs of 6.3 and at pH = 7.2, the LSI is +0.9. Assuming most or all of that GH is from calcium then I think it's worth looking out for light scale.

Thanks Pat. Dang, no surprise I'm getting it wrong .

On the weekend I'll check and report the numbers for each of the bypass levels. I'll also, of course, include the pre Claris but post sediment and carbon filter numbers. There's a 10 ml high range vial with the chloride kit that I don't use, so I'll use that to get better resolution with the API solution.

homeburrero wrote: I wonder if there's any way you can convince them to escalate your support to an expert before pulling the trigger on this system? I would hope they have someone there who has technical understanding of this tricky filter and is aware of GS3 water requirements.

Email sent to Pentair asking for Chloride reduction data per bypass level and for escalation if needed. I will report back.

homeburrero wrote: Yes, but if you were to use the values from your water report for the Upper Merion source, you would have a TDS of 588 ppm, chloride of 173, and alkalinity of 214 mg/L (12 °dKH) and reading these on the Claris Prime capacity chart would put you at only 260 gallons at bypass 3 and 210 gallons at bypass 1.

Yes, I noticed that yesterday so I ordered a TDS meter to better understand my TDS levels. In any case, this filter needs to be replaced once a year at the latest. I think I'll use about 1/2 gallon/day making 3-5 drinks + flushes, so 200 gallon/year is just enough. (Also the Chloride levels here hover around 100 most of the year per Aqua, so it should increase the filter's capacity; not sure how TDS levels vary.)

katkat wrote:Email sent to Pentair asking for Chloride reduction data per bypass level and for escalation if needed. I will report back.

I am not making much progress. Support provided this table, which is not the Chlorides reduction by bypass level.



I will try to escalate to a different person.

That is a handy chart - it does take the mystery out of the bypass settings. In terms of the % TDS getting through for this example tapwater mix you get:

0 - 16%
1 - 26%
2 - 34%
3 - 43%
4 - 51%

So it's fairly fine-tunable over a somewhat narrow range.

I suspect that the percentage of chloride ion as well as the alkalinity and the hardness coming through might roughly match the TDS percentage, but it will be interesting to see if the Claris support folks agree.

I think they were mailing it in when they decided to send you that chart!
It's older and may not even apply to the Prime specifically as it lists 5 bypass settings, not the 7 that are on the Gen 2 filter head which has been out for several years. Also there's no mention anywhere of chloride input level, the reduction of which is a signature feature of the Prime.

Anyway, tomorrow is water test day here so we should have some more relevant info.

As Promised!



I flushed 4-5 gallons with each bypass level change as it's a pretty big filter. Interestingly I was getting roughly 2.5 gpm at all bypass levels, with only a slight decrease at 0 bypass.

Thanks to Pat for kindly agreeing to preview my chart, and suggesting (among other helpful things) that I add the TDS meter calibration factor. I was careful and thorough, but just so you know who's posting this info, I googled the TDS calibration factor and still don't really understand it. In other words, don't bother asking me any questions about water chemistry!

I used the following:
Chloride - Hanna drop kit
TDS - Hanna handheld TDS meter, just calibrated
GH - API fish tank drop kit using 10ml vial for better resolution
KH - API fish tank drop kit using 10ml vial
PH - Bluelab PH pen, just calibrated

Splunge wrote:As Promised!

*** Wow *** I am blown away. Thank you so much Chris and Pat!!! It is much appreciated.

I will definitely need some time and expert advice to figure out how to apply your results to my numbers:

TDS 250 (Zerowater tds meter)
KH - API kit - 6 drops - 107.4 ppm
GH -API kit - 11 drops - 196.9 ppm
PH 7.4 (Tylor K-2006)
Cl 173 (from water report)

homeburrero wrote:think it's reasonable to expect the same fractional result as reported by Splunge ........ If you can get average chloride below 30 or so while still keeping average KH above 40 or so I think you can sleep easy about corrosion risks.

Based on this, bypass 3 might do the trick: KH will be at ~50 (48%) and Cl at 23 (13%). Per Aqua Cl usually hover around 100, so it should be better most of the year.
Filter capacity at bypass 3 given my TDS would be 530 gallons, which should be enough for the machine 0.5 gallon/day. I might even add a drinking water tap (to be also used for convenient flushing.) Filter would be replaced annually, per specs.

Not sure what the impact of the low output PH at bypass 2-3 is? It's lower than La Marzocco's recommendation.

PS - I sent another escalation email today to Pentair but I am close to giving up.
Also - I ignored the comment about the TDS calibration factor for now, hoping that it will somehow magically go away so that I will not need to take another thing into consideration
_____
Guy.