Best top off system?

[Aquattro]

Originally Posted by Reefer Rob

Any idea what caused the float to fill with water?

The seam separated slightly. It was quite old (Kent), but I drained it and applied silicone around the seam and used it for a few more years.
I did notice potential failures when I topped off with kalk, I would get large Ca deposits around the input, but easy enough to clean.