Float switch for ato reservoir?

[Bthomas]

I'm wanting to put a float switch in my ato reservoir to hook to a break out box on my apex to alert me when the water level is low.
I was looking at a magnetic one like this one.. https://www.marinedepot.com/Marine_..._Off_Units-Marine_Depot-MD8145-FIDPAT-vi.html
But one of the questions asked is can it be used submerged and they answered no.
So what kind of float switch can i use that can be kept at the bottom of my top off container?
Wanted magnetic so i could just hook it to the side of the container, not sure how id mount anything else..

 

[Twocorns]

Following, as I'd like to do the same.

 

[wiselyy73]

Get a Tunze ATO and use the smaller magnet for reservoir

 

[ca1ore]

I use Madison floats screwed into a piece of PVC that goes up and over the rim.

 

[Bthomas]

I use Madison floats screwed into a piece of PVC that goes up and over the rim.

Can you elaborate on this a bit? Pics would be great if possible

 

[ca1ore]

Boy, it's hard to take a picture. Maybe this helps .....

Float switch threads into a 1/4" NPT 1/2" slip adapter; adapter is glued into a 1/2" slip coupling; slip coupling is glued to a length of 1/2" PVC pipe. You just have to figure out how best to attach it to the side of the ATO reservoir. With mine, I just connected it to a strip of wood with a male and female 1/2" adapter. You can see that in the picture - though that's obviously not the float from my ATO.