The Tunze Osmolator is the ONLY top off unit that is allowed on my systems. It has an optic sensor and a float sensor back up with alarm. I have 3 of them that I have had for years, and none have failed me yet. Replacement pumps are stocked at J&L Aquatics (and other places too I'm sure) too, so if there is pump failure a quick and easy fix is just a couple days away (J&L has quick shipping).

I have a rubbermaid bin that feeds my tank on a float switch. I turn on my RODI unit once every couple days to fill up the bin that has a float switch in it as well for when I forget to turn it off... oooo.. like right now. My bin sits partially below my sump water level when empty, it allows me to store 30 gallons of RO, with only the risk of 15 gallons getting to my tank if somehow my tank's float fails. I've also got a bin filled in the garage for emergency's. but the 30 gallons is used regularly for water changes.

I've been using the same float for 3 years now, as long as you put it somewhere where it'll get rinsed, there's little risk of the salt build up stopping it from sealing.

But yeah, if I where to buy a nice one I'd go tunze, i did this because it was a $15 float switch and works. Lots of great reviews on the tunze, which is hard with something like this, because the people with the negative experiences would be really ****ed, and speak the loudest.

I've had two Tunze units (one used and one new) and zero problems with either. As said already you want to avoid the pump running dry I suspect this is the cause for all the pump failures. I've also never cleaned my sensors and they've worked perfectly.

Tunze

One of my pumps runs dry at least once a week. I don't know why I haven't killed it yet, it is tough! :lol:

I've got 2 tunze top off's. Lately, my power connector that plugs into the controller doesn't always connect. I looked inside and see there is a build up of salt/corrosion. Has anyone had this issue with Tunze and fixed it? I'm worried one day it won't power-up and stop filling up my tank. I'm not sure what to use to clean it up and how to actually get to it to clean it up.

just unscrew the back if i recall correctly that exposes everything...

Dude all I ever did was a line straight from my rodi line straight to the float switch and it's. Never failed on me since 2002 all these top off gadgets waste of money

You have some horseshoes up your butt. I've seen systems like this fail quite a few times...a friend did this and lost his whole 300 gallon system. A top off is something I personally absolutely will never cheap out on, and I cheap out on a lot of stuff.

What did you use to clean it?

And sorry if it appears that I am derailing the thread. I thought about starting a new one, but since most people are raving about Tunze's, I thought I'd point out that I am having issues with mine. It may just be a quick fix though. Up to this issue, both of mine have worked flawlessly.