I’m a little worried now! I bought the darn Neptune ATK for piece of mind and dependability. It now seems like I should have just went for the Tunze.

Possibly. Although I have had some bad luck with equipment so far. It had been pretty good up until this point.

Fwiw, after that day where it did fill until the float valve shut it off, it has been working fine. I didn't touch it either. But I've been checking every day and waterline is at the first sensor!

Previous to this i used tunze for several years. It lasted about 6years. Needing to replace the pump 2 or 3 times.

Before that I used a simple gravity fed top off with float valve.

I went with the atk thinking the optical sensors would be great, i had them fail while on the road, bought replacements.. had them fail.. then finally when laid off had time to contact neptune support. the internal webpages never updated properly when i first installed the unit and failed optical sensors. they sent me 4 new ones, 2 new ones on my ato, and the 2 old but working ones into my resivoir.. 2-3 months later in the last week or so... both of the ones in the resivoir are failing and i think the one im using for high water is stuck in my ato. when i get some spare funds its time to go back to mechanical floats i guess, right now its a good thing im not working as i can manually fix my top off system. neptune support was excelent to deal with, I guess it might be time to open another ticket.


I still have my origonal jbj unit, its second set of floats are done, i got the atk so i could "SEE" that its working when i am on the road.. instead i could just see that its not working.

I got the ATK for the optical sensors as well. Although in my case, it's the fmm module itself that died. Still annoying to have to wait a week plus for the new one to come.

Update if anyone is interested.


I finally got my replacement ATK module from FedEx today. They had it for a week when I called about it. Apparently they didn't have my buzzer number so it just wasn't delivered and they never bothered to call... Anyways. Plugged in the new module and same thing happened. Keeps filling even if both sensors are completely submerged. So back to customer support I go...


I guess I should have bought the tunze auto top off...

Holee crap.
I hope you get it sorted bud. What a pain.
Nothing like spending good money only to get kicked in the nads.

Have you thought about asking for your money back?
If I were in your shoes, I'd be screaming bloody murder for my money back and wash my hands of the whole experience.

Whoa that sucks.

But maybe something else is awry?
I'm new to controllers and I'll tell ya there's quite the learning curve and I found it quite frustrating to figure out on my own.

For my set up, my top up reservoir (brute can) has a water level higher than my sump, so although the ATK comes with a check valve, I needed to get the solenoid to make it work properly.

I had multiple problems too. Apparently forums everywhere people are reporting issues.

I had sensor #2 fail - they replaced it.
Then my PMUP went bad - had it replaced.

Working now for 2 weeks -s that is good.

I think if I ever have my sensors replaced I might put some silicone on the back of it where the wire enters the sensor. I did this with my old DIY float switch ATO that ran for 8 years. It may be a point of failure.

The PMUP might be a bad design - so if it fails again (if I reach outside of my warranty period) I'll just rig up a different pump. But then essentially I'd be only using the ATK for the optical sensor.

It is frustrating - thousands of dollars spent on the Apex system - pretty happy over the 8/9 years I've had it - but has not been a smooth experience for the ATK.

It could be that something else is up. I haven't changed my setup and it was working for 6 months and then stopped.

My reservoir also has a water level higher than the sump when filled up, but right now it's far lower and it still keeps the pump going.


I think the neptune people are a little unsure as well.



Ya I have noticed lots of people having issues with this. Really annoying since it's so expensive. I am wondering if it's one of my sensors that has gone since I can have them both under the water and the thing is still on and pumping water.


As a update. I have a video call( I guess they escalated) with neptune support on Thursday. Will have to see what comes of it. Really tempted to just ask for my money back and get the tunze ATO. They seem to have good reviews.