u/Lost_Classroom7312

Hi, I'm planning to install a water softener in my London house, which I've been dreaming of doing for a while. I have two places in mind for it.

The first option is under the sink with a socket. The second option is under the stairs without a socket (I'm planning to install a toilet here someday so I'd like to avoid if I can), but this must have a water supply.

Each location has different conditions, so I'll choose either the Poseidon i10 or the TwinTec SI160. I'd like to get the best deal possible.

My questions are:

I'd like to use soft water throughout the house, except in the garden. Can I install it under the sink?
What are the most realistic options, or should I ask a plumber where I can put it before buying it?

Water softener installation place