Best top off system?

[Aquattro]

Originally Posted by Reefer Rob

I'm with the keep it simple group: gravity feed to a mechanical float switch. Too many gadgets, pumps and switches keeps me awake at night.

It would be interesting to hear from someone who actually had this system fail... and why.

It failed once on me due to a leaky float valve. It filled with water and would no longer float, luckily I figured it out before anything bad happened.
Now I use floats and switches, plumbed directly into my RO.