Waitforme Nice…..can’t imagine how that would scale but I’m no expert, as has been said Rob1’s yer man!

    20mg Sodium bicarb to 5 litres will give you an extra 2.4mg/l alkalinity….not worth bothering.

    It’s very difficult to accurately measure 10 or 20mg of anything, with ordinary scales of a 0.00 resolution you might be accurate to 0.1g (100mg).

    Your test would indicate the label on the Ashbeck is significantly out of spec given you’ve only added 2.4mg/l alkalinity with the Sodium bicarb the Alkalinity should be about 27mg/l and hardness should be bout 42mg/l….so I have to ask, did you stop adding drops at the sign of first colour change or did you keep going until it was a “bright” colour? The accurate test would be the one where you stop at the first colour change.

    What is the resolution of your test kit? It say 1drop = 1degree but are you supposed to use a 5ml, 10ml, 20ml sample etc?

    If you made a mistake and added 200mg (0.20g) then you’d end up with about 50mg/l alkalinity with the ashbeck and at least 25mg/l with your tap water……..that’s if the tap water had no alkalinity to start with. So either way something has gone wrong somewhere……or the ashbeck you have is way out to start with.

    Thanks @Rob1 , my mistake, it’s actually 200mg bicarbonate of soda I’m adding to the 5l of Ashbeck.

    The test kit asks to use 10ml and 1 drop equals 1 degree of German hardness, but I used 20ml and just divided by 2.

    According to my water report the alkalinity of my tap water should be approx 25mg HCO3/l

    Does the above make more sense of my test results ?

    Here’s the thing with the test. 17.848mg/l is 1 degree. So with a 10ml sample each drop will count in 17.848mg/l increments. With 20ml each drop will count in 8.914mg/l increments.

    So to reframe your results:

    Tap water: GH >44.8 - <53.714; KH >17.8 - <26.714

    In other words, based on your water report for alkalinity, it appears you haven’t added any sodium bicarb at all.

    Onto the Ashbeck:

    Ashbeck GH 41.88 KH 20.5

    With 200mg/l Sodium bicarb: GH 41.88 KH 45.

    Your test: GH >62 - <70.914; KH >36.6 - <45.514.

    So your test results for KH in the case of Ashbeck appear somewhat accurate, but not for GH…..this is assuming you added 200mg/l Sodium bicarb to Ashbeck and it is within its spec to start with.

    As I asked before, are you adding drops until the first sign of colour change or are you adding until you get a “bright” colour? If you’re waiting for the colour to change to a bright/solid colour then that would explain why your result is so out for GH. If you did the same thing for the KH sample then that will also be out by a similar % (e.g. just of 50% overestimated).

    Basically, it looks like you haven’t weighed the sodium bicarb correctly and have not stopped adding reagent at the first colour change in the case of Ashbeck. In the case of your tap water it looks like you haven’t added any Sodium bicarb at all, as 200mg/l Sodium bicarb in distilled water will give 25mg/l alkalinity (just within your measurement). For your test to be accurate for tap water you would have to have almost 0 alkalinity to start with.

    So all in all it looks like the GH (and maybe the KH) test was not correctly conducted for Ashbeck and Sodium bicarb was not accurately measured for your tap water.

    Measuring 200mg means you’re probably going to be out by up to 100mg….maybe more depending on the response time of the scales. The spec sheet of the scales will usually tell you how accurate they are e.g. accurate to 100mg, respond to 50mg etc. Usually, they have a minimum threshold below which they don’t work properly too, so they might say accurate to 100mg from 500mg etc. This is why making a concentrate is recommended….though logically volume should be accurate assuming you can find a scoop of the right size.

    To conduct the test accurately, shake the reagents and hold them vertically over the sample to release drops of the same size (holding at an angle will give you different sized drops). Also, worth checking the expiration date. Stop adding drops the moment the colour changes from whatever to Green and Red. You obviously have to mix after every drop, I do it in a cup and just stir as I’m adding drops and wait a moment between each drop.

      Rob1 10ml sample each drop will count in 17.848mg/l increments. With 20ml each drop will count in 8.914mg/l increments.

      Rob, unless his test kit is for 10ml sample, the standard drop kit — mine — is for 5 ml. So, 5 ml sample of 1 drop will be 17.848 mg/l and will be a quarter that for 20ml. Happy to be corrected! 😊

      Edit: Perhaps, this isn’t an API test kit. The KH test colour is red in his case, while it is yellow in mine.

        @Rob1 , thanks for taking the time to respond.

        I haven’t added anything to the tap water, just to the Ashbeck.

        @LMSC According to the kit I have the sample size should be 10ml but I’ve used 20ml to try and get a more accurate reading.

        I’ll run both tests again tomorrow and pay particular attention to the moment I see any colour change. And be sure to drip vertically.

        My scales display in 0.01g increments but doesn’t say how accurate they are.

        • LMSC replied to this.

          Waitforme Ah. That’s different. Rob’s correct for your sample size. Thx for the clarification mate.

          Edit:

          The spec should tell you the minimum, which will be the accuracy level.

            So I carried out the tests again, twice for both the tap water and the Ashbeck.

            Only the Ashbeck has the 200mg of Bicarbonate of Soda added per 5l.

            My scales appear to be accurate to 0.01g

            I shook the reagents prior to dropping and dropped vertically into the containers.

            The results for the tap water were the same as I got previously in both tests today , total hardness 5 drops in 20ml / 2 giving 2.5 degrees German, and 2 drops for Carbonate hardness in 20ml / 2 giving 1 degree German.

            The Ashbeck test gave results of 7 drops for Total hardness in the first test today and 6 in the second test , giving 3 - 3.5 Degrees German and 6 drops for carbonate hardness in the first test and 5 in the second test giving 2.5 - 3 degrees German.

            Do these results make any more sense @Rob1 ?

            Not really, not based on the spec of Ashbeck. It could be really inconsistent for all I know though. Presumably, the tap water is reading at the lower end of the samples taken from the water authority?

            The carbonate hardness, or alkalinity, should be about 24mg/l from 200mg in 5 litres. So Ashbeck should be showing about 44mg/l based on the label so your test seems accurate for that.

            If you want to verify the accuracy of your kit the only way to do it is to do two samples with different amount of sodium bicarb added and measure the predictable difference.

            Thanks @Rob1 , if my results for the tap water are accurate is it boiler safe water, it would appear to be better than the Ashbeck is my understanding?

            Local authority test results for my postcode are 25mg HCO3/l and 31.24 CaCOmg/l , although they were taken in 2019.

            I must carry out the test with different levels of Bicarbonate added to the Ashbeck.

            One final question , is there a particular test kit for home use that is more accurate than another ?

            Ok , one more ….. Is a TDS meter worth using ?

            Thanks again.

            Rob1 Hi Rob. How do you put this 400ml only into the service boiler as I’m assuming you wouldn’t want it in the brew boiler?

            • Rob1 replied to this.

                simonc

                The excess from the distiller per run is stored away and is used for making concentrates and filling the service boiler. I remove the anti-vac valve and pour it in rather than run the pump on and off until the boiler fills, mainly because it’s less faff than messing about with the reservoir and I don’t have to listen to the pump running.

                  7 days later
                  7 months later

                  Got the kit in the end and tested water from the boiler. Still confused about what’s what after reading this thread again so I’m just being thick !!

                  Steam boiler 7 weeks after full drain and weekly cup draws.

                  20 ml samples 21.3 Celsius. only have 5 ml tubes so used cups and mixed using a spoon after every drop (hopefully this doesn’t alter the score)

                  TDS reader - 33

                  GH - 10 drops = 179 / 4 = 44.75

                  KH - 7 drops = 125.3 / 4 = 31.32

                  Photos of the final colours

                  Water from osmio zero with remineralisation cartridge

                  20ml samples 22.5 Celsius

                  TDS reader 34

                  GH - 6 drops = 107.4 / 4 = 26.85

                  KH - 5 drops (light yellow)/ 6 drops  (brighter yellow) = 89.5 / 4 = 22.37 (light) / 107.4 / 4 = 26.85 (brighter)

                  mailto:kafar@btinternet.com

                    prezes

                    If you held the droppers perfectly upright and squeezed on drop at a time, you stop at the first colour change and your results will be consistent….

                    So with that said.

                    Service Boiler:

                    GH - 10 drops = 179 / 4 = >44.75 <49.23

                    KH - 7 drops = 125.3 / 4 = >31.32 <35.8

                    RO Water:

                    GH - 6 drops = 107.4 / 4 = >26.85 <31.33

                    KH - 5 drops = 89.5 / 4 = >22.37 <26.85

                    Testing your service boiler water 7 weeks after the last drain and drawing a cup of water a week is of little use unless you’ve managed to just about identify the point it might become a problem. Depending on the temp you run your service boiler at (assuming 125c) it’s about time to empty the boiler again. A small increase in alkalinity and you’ll start to get some scale.

                        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?

                        mailto:kafar@btinternet.com

                        • 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

                                    mailto:kafar@btinternet.com