Based on my experience with the Evo Leva (same boilers as the Minima), I’d suggest the simple additional step of drawing around a cup of hot water from the service boiler after steaming milk when using the Osmio Zero and the remineralisation cartridge.

I’ve done so for over a year and the TDS of the hot water (after letting it cool down) stays stable at about 55 ppm… and thus I haven’t felt the need for a monthly full flush but YMMV

    @LMSC Eiffel Good tips.

    I have no problem in drawing a cup from the service boiler after steaming milk and monthly flushing.

    Planet Organic have a good deal on, so I think I’ll make the jump.

    @Eiffel How are you testing your TDS?

      I have a cheapo “TDS-3” meter bought from less than £4 on Amazon.

      While I don’t know how accurate it is, I get distinct but consistent reading over time when measuring tap water (upper 200 ppm), water straight from the Osmio (30-40 ppm) and from the service boiler (~55 ppm).

        Eiffel I think I need to get one in the next Amazon Prime Day sale and see where I’m at before and after with my tap water.

        I’m in NW London (Affinity Water) and PPM looks to be around 352. Hopefully I can get this down somewhat with the OZ.

          Also, get a drop kit, measure the GH and KH of your water from the boiler at room temperature. Test on a sample of 20 ml or 40 ml for each test, multiple 17.9 by number of drops and divide the output by 4 (if 20 ml) or 8 (if 40 ml). You can do it on your monthly full flush.

            LMSC Absolute star!

            Going to make an excel spreadsheet so I can see month by month what my GH and KH is.

            • LMSC replied to this.

                Verion Sounds like a plan! :-)

                Btw, you will find an excel under @Rob1’s signature. Please take a look. It’s pretty good.

                  So my OZ turned up to today and it’s set it up and ready to go.

                  Testing with my £6.99 TDS meter from Amazon, regular tap water at room temperature reading is around 409. OZ water at room temperature is around 49.

                  That’s quite a drop of 88%.

                  I need to get the KH/GH test kit from my local aquatics supplier, but the water looks like it’s in a good place for when my Minima turns up.

                  10 months later

                  Hi all. I didn’t want to start a new thread so hoped I’d get an answer here……..I’m looking to buy an OZ, for when my Minima arrives. I understand the need to sanitise the OZ but can’t get my head around why it would need descaling (as mentioned in a this and other OZ threads) could anyone answer my (maybe stupid) question please?

                  P.S I live in a fairly soft water area.

                  Thanks

                  Al

                  • Rob1 replied to this.

                    Abcan not entirely sure….scale forms at low temperatures when water is supersaturated. Could well be it’s just to get the salts off the filters. In short, you don’t just get scale from heating the water…. though I believe the oz does that too.

                      Not sure on this one either. The filters are removed for descaling so they don’t get any treatment. If the operational filters remove scale from the water, then surely you are just descaling the route from reservoir to the filters? A short piece of tubing. Is it then that the only part of it that’s descaled is the reservoir tank and pipes to filters?

                      Edit - I suppose whatever is left after the filters starts to deposit over time especially around the heating element?

                      Not necessarily, after filtration it’s not going to heat enough to scale. Must be pipes to filters. That’s assuming the heating element only comes into contact with filtered water.

                      3 months later

                      I just tested the output of my Osmio zero. Filters are 11 months old. KH is 26.9 and GH was negligible (seemed to turn green after first drop and remained green thereafter with more drops added). This confuses me as I thought KH is carbonate hardness (hardness due to bicarbonates alone) whereas GH is general hardness (hardness contributed by all contributers), hence I would have imagined GH would be greater than KH? Any thoughts on this? I use the API drop test kit, 40ml sample, results divided by 4

                      • Rob1 replied to this.

                        JahLaza It’s a measure of alkalinity which is contributed by more than just bicarbonate, though bicarb will be the main source. The filters are likely much better at removing calcium and magnesium than they are bicarbonate and other smaller things due to particle size.

                            Rob1 does this mean there is some carbonates and nothing else? I realise it’s a pretty crude test, but in simple terms. And pertaining to the Osmio operation,the remineralisation has probably stopped supplying back some? Or do these results indicate it’s removing everything and the remineralisation cartridge is adding the 26.9pm I got? I always leave that cartridge in

                            • Rob1 replied to this.

                                40 ml sample divided by 8. It may not matter much.

                                  LMSC apologies it’s 20 mls of a sample, the result divided by 4

                                    JahLaza Oh, ok I assumed based on the title of the thread that the remineralisation cartridge wasn’t being used. It’s supposed to add alkalinity and hardness back in about equal measure, I think. It may be exhausted and the output represents pretty much the results of filtration. I can’t say if the alkalinity is from carbonates or not. Probably. Osmio are reluctant to say exactly what is in the remineralisation cartridge, could be phosphates or citrates.