Rob1 Thanks Rob.

I tend to refresh the boiler every 8 weeks so was about to do it. My service boiler is set to 129 Celsius

  • Would it it be best to test the water weekly and as soon as notice increase in KH assume it’s time to refill ?
  • Is the water fed acceptable to should I change something to achieve the ‘sweet spot’ between scaling and corrosion?
  • Rob1 replied to this.

    prezes You’ll see an increase after you steam, so no not really. Technically there is no sweet spot as both corrosion and scaling change with temperature. Increasing alkalinity a little more to 40-50mg/l will be good for corrosion it likely won’t for scaling. Whether or not the corrosion will ever be something you suffer for is another matter. Plenty of people have been using ashbeck and water of a similar spec to your RO long term without reporting issues.

    If I were you I’d be increasing alkalinity and descaling the service boiler as I wouldn’t want to brew coffee with water that low in alkalinity, but if it doesn’t bother you there’s no reason to not carry on as you are. I’d check the water after a week and you can just calculate from there how much additional hardness and alkalinity you will get over x weeks assuming you tend to make the same number and type of drinks and just flush according to that rather than try to test and catch it exactly at the point you need to empty to boiler.

    MWJB I can see you are very well informed re water quality and certainly a lot more than I am. Could I ask your opinion on using osmio zero with their cartridge supplied fitted. I appreciate it introduces some calcium carbonate (I believe) but apparently such a small amount that the water is still considered soft. Would this be ok to use or is any level of calcium or magnesium a big no no to espresso machines.

      coffeealex Rob1 is your man for that question. I use water with calcium and magnesium in my Sage.

      All water (very soft, soft, hard, very hard) has calcium carbonate in it, unless you take it out.

      Companies like La Marzocco specify how much how hardness they recommend, it’s more than none.

      2 months later

      @Rob1 decided to test the water from Osmio as replaced the filters for the first time and used hard water filters. Came back quite low so unsure if should be adding something to water to increase alkalinity before feeding the boilers?

      Osmio new filters /hard water filter/ with remineralisation cartridge

      20ml sample 22 degrees
      TDS reading - 14

      GH - 2 drops 35.8 / 4 = 8.95
      KH - 2 drops 35.8 / 4 = 8.95

        prezes Are you sure those numbers are correct? With new mineralisation cartridge, I would expect the alkalinity of about 35mg/l to 45 mg/l. The GH look correct, though it can even be about 15/16 mg/l. These are my average during the last 20 months of use.

        Perhaps, your hard water filter is the reason! How does the hard water filter work with Osmio Zero? What are your pure RO readings? Thx

        coffeealex I appreciate it introduces some calcium carbonate (I believe) but apparently such a small amount that the water is still considered soft. Would this be ok to use or is any level of calcium or magnesium a big no no to espresso machines.

        I think @LMSC , @DavecUK and @dfk41 , and there may be others, have been using the Osmio with the remineralisation cartridge for a while now, so you could also ask them. 👍

        I haven’t had any issues so far. I hardly test the water from brew boiler. I do in the case of steam.

        The last test on the brew boiler was in Nov 2021

        • GH 3 drops avg = 13.43 mg/l (one year range was 13 mg/l to 25 mg/) l
        • KH 8 drops to average 35.8 mg/l (1 year range was 36 mg/l - 55 mg/l)
        • TDS 69
        • Temp 18.4C

        The last reading on the steam boiler was on 21 Nov 22 (full flesh every 6-8 weeks and a draw a small cup after steaming)

        1. GH avg  = 6.71 mg/l (16 months range was 6.7 mg/l - 20 mg/l)
        2. KH average 29.09 mg/l l (16 months range was 29 mg/l - 50 mg/l)
        3. TDS 67
        4. Temp 19.7

        The new mineralisation filter will skew the reading to the top of the range and then starts drifting lower.

        prezes I’m guessing the remineralisation cartridge is spent as your water just reflects what you’d expect from straight RO water.

          Rob1 this would make sense but I replaced all the filters at the same time including the cartridge.

          I will repeat the test tomorrow and see what I get back

          Second attempt this morning and it took 4 drops for first change of colour…
          GH - 4 drops 71.6 / 4 = 17.9
          KH - 4 drops 71.6 / 4 = 17.9

          Could be the water needs to sit in the tank to be effectively remineralised. If you filter and dispense straight away maybe it doesn’t work?

            Rob1 I was thinking this might be the case but I changed the filters last Sunday so been a while. The water dispensed wasn’t freshly filtered. Maybe the remineralisation filter needs time to be fully active?

            • LMSC replied to this.

              prezes No! The mineralisation will start working immediately. You have been using it for a week now; if you have never drawn any water after changing the filter, a litre of water in the internal tank was from the old filter.

              The longer the water sits in the pipe (between tank and dispenser), the greater will be the concentration. The first draw in the morning will have more mineral content.

              Could you tell us a bit more about the hard water filter? How is it connected to the mains and Osmio Zero?

              The colour of those two glasses look similar to my eyes. One should be green and the other yellow, IIRC, if it is the API test kit.

                LMSC I run 3.5 litres of water through new filters before using the water and would have at lease another 20 through before first test.

                The hard water filter is another option you can my from osmio if you live in quite hard water area. The filters the unit came with weee standard but as replacement I purchased those https://www.osmiowater.co.uk/osmio-zero-ip-ii-portable-reverse-osmosis-replacement-filters-pack-hard-water.html .

                Don’t tell me about colours ! As you meant to stop at the first sign of change of colour I am getting mental here trying to establish if this is light yellow or pale green !

                • LMSC replied to this.

                  prezes Don’t tell me about colours ! As you meant to stop at the first sign of change of colour I am getting mental here trying to establish if this is light yellow or pale green

                  Did you read the instructions ? One of them, which I think is alkalinity, will take more drops than the other; and, that will turn from blue to yellow.

                  The other, I think GH, will turn from amber to green!

                  For an example, I require about 12 - 13 drops to get the desired colour on my KH test kit to get a value of about 30 mg/l using 40 ml sample.

                  These are for the API test kits.

                    LMSC of course I read them back and forth few times. On my kit KH is blue to yellow and GH orange to yellow.

                    The difficulty is that reading through the posts here you are not meant to wait till the colour is solid but only to the first sign of change which I found a nightmare to assess ! Especially from orange to yellow.

                    Sometimes I wish to be blessed with ignorance and thick wallet ! Don’t worry about it at all if machine breaks down I’ll get another one lol !

                      prezes The difficulty is that reading through the posts here you are not meant to wait till the colour is solid but only to the first sign of change which I found a nightmare to assess ! Especially from orange to yellow.

                      KH > blue to yellow > easy as you can’t miss the change.

                      GH is difficult given your colours. You may either try 40 ml sample so that it requires more drops or keep the 20 ml sample, add a drop more to get a confirmation. You can then take an average of the two (one without an extra drop and the other with a drop more).

                      On these basis, while your GH looks ok to me, the KH looks too low. May be, you want to run your test of pure RO to compare it with what you have. To get a pure RO sample, you need a blank mineralisation cartridge, draw out all the water from the internal tank and refill the tank as a pure RO.