Automatic Top-Offs

How many of you fellow reefers use an automatic top-off? If you use one, what type do you use?
How good of a job do they do?
I have alot of evaporation in my 125gallon, where I am replacing roughly 2gallons or so a day...it is a pain!
With this, I am wanting to address this problem asap.
I want to look into the idea of purchasing a automatic top-off, unless there is an easy DYI solution to this...
Thanks in advance for any feedback you may have to assist me in this :thinking2 matter!!!!

 

I have a Kent float valve in my sump hooked into my RODI unit. Works fine.

 

Like blade runner I use the Kent's since they came out and I have never had a problem with them. Before Kent's I used a style that I used to get commercially for water chiller cooling towers Just cost a lot more and did the same job. I also use them in a holding tank tee'd off to keep or store new water just in-case also a Kent in that Bucket also.

 

I had a Kent Float on my 30 and even dosed kalk through it without trouble. I cleaned it occasionally.

On my 20 I went with the Tunze Osmolator. I use it on my turtle tank now. It's expensive but for an electronic unit it does not let the water go down very far before it activates the pump. Easy to clean and you don't have to do that too often either.

 

Funny, I have a "commercial" valve on my Rubbermaid 100g holding tank. It fits over the lip instead of having to drill the tank for a Kent. I just don't trust it as much as the Kent.

The only problem I've had with the Kent is in mounting. The plex in my sump is too thick and I needed to counter sink the hole to have the threads reach the nut. This is a non-issue for most applications.