I dont even trust those for my lights, let alone for something as important as an ATO:razz::razz:

:lol: I think some people just have trust issues :wink:

my DIY auto top off consists of three float switches, two on my sump (one for redundancy) and one in the reservoir. 5v runs through these and actuate a relay for my pump. I would never trust it if I connected the pump directly to them. It works great so far. :biggrin: Almost a must with a skimmer

I love mine. It is fed by a 5g bucket so even if it goes haywire (never has and hope never will) adding 5g of fw to a 165g with 90g wide sump will not have a major negative effect. I top it off every 4-5 days (glass covered display). This would not have worked on my 210g with 75g sump (all open top) cause I lost 3+g a day on that system.

I have one of these:

http://autotopoff.com/

Its has never failed. Used to use a Tunzie, I was buying new pumps for it every 3 months until the controller gave up.

CONSIDERING!?!?! Really? This is a no brainer. My Tunze broke a couple weeks ago, and it makes me angry to do it manually. That said, my whole tank makes me angry right now, but that's a different story.

used to have a gravity fed system with a float valve that failed once a year. I'd replace it and it would be good for another year. Finally when I set up my most recent tank I decided to look into a float switch. Turns out one came with my controller so I set that up. Its failed on me a couple of times (small brittle stars get into the floating part of the switch and jam it) but my topoff tank is small enough and the main tank large enough that if the whole topoff tank ends up in the sump, its not a huge deal.

I asked the same question a couple months ago and while most people responded Tunze everyone else just said what they currently had was the best. So I went a different direction and started googling what systems have failed and why. I couldn't find any instances were a Tunze ATO caused any damage or overflows. Lots of pumps dying but usually due to owner not filling up the water. Other systems had more problems but I'll leave you to research any particular methods you are interested in.