pete10uk How do you clean out a water tank.
I have a Lelit Mara and just use warm water and a vigorous shake every alternate fill up.
I used to use a Milton tablet, but I found the tablets went off before I ever used them all up. So I have a thing that uses electricity water and salt to make hypochlorite. I now simply spray the insides of tanks with that each week or two, let it sit for 10 minutes, then rinse out. If a little bit is left, it causes no problems.
The trick whatever method you use, is to spray the inside of the tank and leave it for 10 minutes…
P.S. Used milton can’t be kept and should be used, then discarded. If you have plastic water bottles, sponges, knock boxes, etc.. you can do all those at the same time.