I use the Kent and have found it to great although it needs to be cleaned
every 6 months or so if you are using additives in your ro water.
the hole size was 14mm and from the centre of the hole to the water surface
it is 20mm
and that's with the float adjustment set in the middle.
Regards Tony
My Tank:

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www.users.bigpond.com/fishmann/


"Pszemol" wrote in message
...
I have purchased a float switch for my RO output tank.
I need to drill a hole to scew it to the wall...
What is the relationship of the hole hight to the water surface?

I could experiment with it, but I guess you guys have it already
figured out if you use this switch. So - is the hole above or
below the water surface and if so, what is the exact distance?