Question about ATOs

[Neckbone]

So I’m looking at an ATO system. I noticed theres a Tunez Osmolator and a Tunez Nano (for < 55gal). How is an ATO dependent on tank size? When the water level in the sump drops, the pump kicks on and tops it off. What difference does the tank volume make? The ATO keeps pumping until the sensor/switch hits the water (provided I have enough in the reservoir). Am I missing something?

 

[mcarroll]

There's a software shutoff as well on the Tunze units to prevent dumping the whole reservoir in the event that "something" happens to the main sensor(s). It's timed based on tank size.

 

[Neckbone]

There's a software shutoff as well on the Tunze units to prevent dumping the whole reservoir in the event that "something" happens to the main sensor(s). It's timed based on tank size.

It’s not programmable? Can’t you just adjust your reservoir to a volume that’s less than what would overfill your sump? Besides, an ATO that’s made for smaller tanks should have a shorter shutoff timer than a larger tank. So theoretically, you’re only in danger if you use the bigger Tunze on a smaller tank. Or should I say sump? The ATO would go in my sump and the tank level stays the same based on the overflow box.

 

[adtravels]

I have a tunze nano a to, the standard and the Neptune afs. To date the most reliable has been the tunze standard. I had some significant issues with the tunze nano, it would fail periodically at the controller for some reason. The apex afa is ok so far but I have had some issues with code and troublesome email alerts.

Best set and forget for me is the tunze standard. It has been going since early 2014 on one of my systems. The pump has failed once in that time although I would change the pump every 2 years if using just ro water and every year if using kalkwasser

 

[mcarroll]

It’s not programmable?

It's tweakable, but shouldn't be necessary under normal conditions.

Can’t you just adjust your reservoir to a volume that’s less than what would overfill your sump?

I'd suggest following that advice no matter which ATO system you choose.

Besides, an ATO that’s made for smaller tanks should have a shorter shutoff timer than a larger tank.

That's how the Tunze's are set up.

Most ATO's are just lacking the fancy software and are only controlled by the float sensor(s). (Like these DIY kits.)

 

[Neckbone]

Hmmmm. I sense marketing malarkey. You get more features with the full size which you can use to justify the price increase, but I think marketing the nano for smaller tanks only is a bit disingenuous.

 

[tiggs]

It's not so much that the Tunze nano can only handle smaller tanks, but it's more of a matter of the smaller footprint that can actually fit into a nano. The Tunze 3150 (standard) is definitely the better device overall (and the best ATO on the market, IMO), given it has dual sensors with one of them being optical. The other difference between the two is the 3150 goes into test mode every time the power is reset and it pumps for a bit (I believe 30 seconds), while the nano doesn't do this. The main reason being 30 seconds of top-off water into a nano could cause a significant SG swing.

For the record, I use the Tunze 3152 nano on my 14G and haven't had a single issue with it. It definitely would work on a larger tank (within reason) as well. With that being said, if the 3150 would fit and didn't go into test mode (I only give power to my ATO outlet for 30 seconds every half hour as a safeguard against the sensor getting stuck or the unit malfunctioning), I'd definitely use that.