autotopoff.com setup plan?

[farfromsea]

I want to setup my ATO using the product available on autotopoff.com. I have unfortunately always struggled with physics and this type of DIY-arena so confirmation that my plan isn't garbage would be really helpful.

What I need:
an ATO-pump-controller system that will allow me to top-off my sump with RODI. Reservoir is going to be a plastic 5-gallon jug that my LFS sells water in (max 24" tall?). Sump is a 29 gallon long which only holds water that goes to a height of 8". I will be adding water to the reservoir by hand; I do not have an RODI unit pumping into it.

Purchase plan:

• double controller w/bracket (will this then shut off if the reservoir is too low so the pump doesn't burn out?)
• Fountain Tech FT-70 pump (max head height is 25", enough?)
• 5/16" tubing (what the above pump requires, other option is 1/2" not sure that wider is necessary for my goals)
  

Am I missing anything? Main issue is I don't know if the double controller means that it will shut off if the reservoir is empty. This is what appeals to me about the JBJ controller. If it doesn't maybe I should just get the JBJ? Doesn't seem like the Tunze nano has that feature plus it is twice as expensive.

Thanks for any feedback!

 

[LXXero]

it sounds like the "double" is intended to prevent from filling the tank too high

but you could probably invert the sensor and use it for a reservoir too low switch as well. don't see why not. it describes it as a failsafe as opposed to the primary function, so chances are it's "off" only and "on" is only controlled by the main float. just mount it upside down or possibly flip the float around (some let you take the float off and flip it and it will reverse the function)

 

[farfromsea]

Okay I think that makes sense. But then it sounds like I need an additional something if I want the controller to be "off" if the sump becomes filled enough *and/or* "off" if the reservoir is too low. I should probably email the autotopoff.com guys and ask I suppose. But I imagine I probably need more float switches. Completely unsure if the controller is capable of handling this. I am so visual I really need to be holding this type of thing in my hand to figure out what is going on. I've watched a youtube video or two but it was unfortunately not enlightening

 

[LXXero]

from how i read it, the single uses the main float for on/off purposes, and the double is the same, but has a "high cutoff" that disables it. if that's truly how it functions, then you can just use it as-is, but flip it upside down so the high cutoff is now a low cutoff instead.

however if it uses the 2nd switch to act as a water height cutoff, then...that won't work. definitely can't hurt to ask.

 

[farfromsea]

What exactly is the difference between on/off versus disabling it? I mean wouldn't it always be off if the water is as high as you want it to be (i.e. the float hasn't dropped down)?

 

[LXXero]

so the main switch would be: pump off when it's up, when the water is at the correct level, and pump on when it's down, when your water is low and you want the pump turned on to add more water.

from my understanding, the 2nd switch is an emergency "off", it never turns the pump on by itself directly. however, the pump wont turn on unless this switch is down, and would shut the pump off if it were ever to go"up".

you could alternatively switch the function of that 2nd switch by inverting it and sticking it in your reservoir. Then, when it has water, things are normal, but when the water level drops, it would act as the emergency "off" switch still. So basically make it so that instead of it being required to be down, it's required to be up, by the water level in your reservoir. it may be as simple as literally mounting it upside down or taking off a clip and flipping the float around.

Think of it another way: the switches are more than likely wired in series. So basically, both switches have to be closed for the pump to come on. If either switch is open, the circuit is not completed and the pump stays off. Both switches need to be closed so that the circuit is completed. The switch being closed just depends what position the float switch is in, and you can change what "closed" means by literally positioning the float switch one way or the other, or in some cases, flipping the magnetic float portion only.

 

[Bent]

I have this exact same setup and your plan is good. A few things:

1: the secondary switch is an emergency switch. If the water level raises the secondary float it will shut the pump off. Place this switch right above the primary switch.

2: the fountain pump is a good pump. Mines been working like a champ since I set it up.

3: clean the float switches every couple months. The easiest way to do this is to put the ATO pump on a switch panel like with those DJ switches, switch the pump off, pull the switches, disassemble them and clean with vinegar.

4: another good thing to do as another fail safe is to use a bulkhead float valve as well. Like this:
https://www.amazon.com/Kerick-Valve-MA052-Float-Adjustable/dp/B0077RAP1I

Now this valve may not be the right size for your application, so get the right one. But put the valve at the highest tolerable water level in the sump. So now, even if the secondary switch were to fail and not shut the pump off, the valve will stop the flow of water to the sump and prevent a flood.

 

[farfromsea]

Thanks everyone.

So I have continued to look into this over the past few days. Turns out the space under my cube is so small that I can only fit a custom reservoir that holds 4.8 gallons. Needless to say the issue of the sump overflowing if all of the water comes out because of this small quantity of water. I know some people put their reservoirs outside of the stand in one of those things used to hide cat litter boxes but the husband will not allow that so that is that.

I spoke with Paul of autotopoff.com really helpful guy.

He noted that it isn't really worth it to cause a lot of hassle over a $7 pump and that in his experience they have never burned out because of the scant amount of water that remains in the ATO. So, I'm no longer concerned about that.

He informed me that because the height of my reservoir is higher than my sump I may have a problem with a siphon occurring.

Here is his suggestion which I am not sure I have grasped entirely.

The only other thing you'll have to worry about is preventing a siphon since the max level in your reservoir will be higher than the level in your sump. When the ATO turns off, water will continue siphoning from your reservoir to your sump until the two water levels equalize. To prevent it you need to get air in the tubing above the max level in your reservoir. You can just poke a hole in the tubing but then water will come out when your topoff pump is running. You can install an "˜air line nipple' in that hole in the tubing then run tubing from there to your reservoir or sump, just leave the end of that tubing above the water. You could also run the vinyl tubing into a length of rigid pvc that extends up higher than your max reservoir level like in the attached pic. This will create an air gap where the rigid tubing meets the vinyl tubing above the max level in your reservoir.

I don't really know what he meant by an air line nipple. Do I have to cut the tubing and then insert a short piece of tubing in that hole like a little tail? If so not sure how that would exactly keep the water going from the pump into the sump yet not spray out everywhere from the hole...

He attached a pic of the pvc setup and to me it looks like it is just a way to keep the airline tubing out of the water. (see pic attached) Couldn't I just achieve this by clamping it to the side of my sump or something?

Melev sells a kit for $100 that includes pump and siphon breaker, no bracket. But autotopoff still wins price wise going to be like $60. Melev's kit has an optical eye but I really don't think that is necessary and is just more technology apt to failure.