BEST Auto Top Off (ATO)

revhtree · Dec 20, 2016

You'll see the acronym ATO mentioned a lot on the forums. It stands for Auto Top Off. What is an auto top you ask?

An Auto Top Off System automates the addition of water to your saltwater aquarium that is lost due to evaporation.

I have used a couple different ATO's in my time as a hobbyist including a JBJ ATO and a Tunze Osmolator. I currently am using the Tunze version.

The good thing about these systems are the fact that they eliminate an almost daily chore. The problem with these systems are issues that can happen with any equipment we use in our tanks. They get old/used and parts fail.

So what about you? What has been a really good ATO in your experience?

MaiReef · Dec 20, 2016

Autotopoff.com has one that has dual pvc covers that has worked for 3 years and still going in my refugium and I have only randomly cleaned the outside. I have a mag pump on it now and going to a RIO because I need more flow going through the Kalk Stirrer.

BigJim · Dec 20, 2016

I prefer the Tunze Osmolator. I recently had an issue where I neglected to clean the sensor for a while and it stopped working. I heard my return pump sucking a little air and realized the issue pretty quick. I was lucky to have no issues because both heater we partially exposed to air and on. Now I have a reminder in my calendar to clean my ATO sensor monthly. They definitely require some routine maintenance to be safe.

AdamNC · Dec 20, 2016

I've been using a Tunze nano 3152 for over 2 1/2 years with no issues. Even been using Kalkwasser through it. The key thing to any piece of equipment is to keep it clean and keep the electronics part of it dry. At least a semi annual vinegar soak is what is needed for the pumps and float switches.

BMW540 · Dec 20, 2016

I have used one from autotopoff.com and currently am using a Smart ATO. Both are great, but prefer the features of the Smart ATO: beeping when the reservoir is empty is very helpful.

pelphrey · Dec 20, 2016

Just switched from the JBJ to the Tunze 3155. So far I do like the Tunze a lot more, the noise the pump makes annoys me but at the same time lets me know that it is running. I really need to crack the Tunze display open and turn the alarm off or as low as it will go. I am using floats in my sump on the Apex BOB so the alarm in my case isn't needed.

cromag27 · Dec 20, 2016

Spectrapure can't be beat. their peristaltic pump comes with an unmatched warranty, you don't have to worry about back-siphon, and if you get a model with a controller you can completely customize the process. I've used jbj, hydor and tunze. all had issues.

Terence · Dec 20, 2016

I think you can see some MACNA video out there of a gray and orange one that should be out pretty soon... [emoji41]

redfishbluefish · Dec 20, 2016

I'm a DIY kind of person, so my ATO on my DT is an AquaHub Premium kit that requires minimal assembly and skill. What I like about this ATO is that there is a secondary float switch offset from the primary so that if and when the primary fails, the secondary catches it. Can't beat it for $40 bucks.

Now I have had to change the primary float switch because it failed....just did it for the second time....after about 7 - 8 years.

I went on to do a full DIY float switch were I purchased all the parts myself. I was able to do this one for about 12.50 bucks.....and I documented that little DIY project HERE.

Regardless of the ATO you purchase/build, I would highly recommend you get one that has a secondary switch.

Cory · Dec 20, 2016

Ive only owned one

I use an Avast Marine ato. I chose it because it made sense. It uses a peristatic pump, a pressure sensitive switch and a secondary float valve.

The pressure switch is vastly superior to mechanical float valves. Why? With a float valve, things can get stuck causing it to stay on or off. With a pressure switch, it cant stay stuck on or off because the chances of something covering its pressure sensitivs area is not likely. Its based on water pressure, not really a close or open. The pump is pretty queit too.

The only negative ive had is the hose it came with developed a hole after 2 months and had to be replaced.

joshporksandwich · Dec 20, 2016

I've only used the puratek one. I'm happy with it with the exception that both solenoids touched salt water and stopped working. Luckily puratek is local to me and the solenoids were replaced for free even though it was my own stupidity that messed them up.

Philt56 · Dec 21, 2016

I have the Smart ATO and have noticed that the inside half of the sensor will start to rust! I had 2 of them (one was sent as a replacement due to a different issue) and both of them developed rust. The first one fell apart , it was corrided so badly.

Have others seen this? Doesn't seem good for a reef tank.

cmcoker · Dec 21, 2016

Cory said:
Ive only owned one

I use an Avast Marine ato. I chose it because it made sense. It uses a peristatic pump, a pressure sensitive switch and a secondary float valve.

The pressure switch is vastly superior to mechanical float valves. Why? With a float valve, things can get stuck causing it to stay on or off. With a pressure switch, it cant stay stuck on or off because the chances of something covering its pressure sensitivs area is not likely. Its based on water pressure, not really a close or open. The pump is pretty queit too.

The only negative ive had is the hose it came with developed a hole after 2 months and had to be replaced.

This.
But my hose is still fine after 3 years
And I use and aqualifter pump with the avast ATO sensor

DanConnor · Dec 21, 2016

Another Avast user here.

Triggreef · Dec 21, 2016

You guys and your fancy ato's kill me. Electronic float switches, peristaltic pumps, controllers, aqualifter this, sensor that...

I love my diy gravity feed set ups, like $30 for a float in my sump and done. Valve drops, water feeds. No extra electrical power. No extra parts to fail. Gravity is constant. No issues in the many years I've had 3 ato's going simultaneously.

Only thing is having to flush the line periodically since I dose kalk in my top off sometimes it clogs but it takes 2 seconds to clear.

Broadfield · Dec 21, 2016

I'm currently using the Puratek Auto Level Controller... and I must say it's amazing. Absolutely worry free with backup.

Not a single thing mounts in the water. The level sensor mounts on the outside of the sump/container and is as tiny as can be. It can even read through a solid colored surface... like black acrylic or plastic. As a backup, it has a programmable timer for max runtime. My ATO pump runs for a total of about 7 minutes/day. So I have the max runtime set to 10 minutes/day. At the 10 minute mark, it will emit a screeching alarm tone that has to be turned off. If the sensor did fail for some reason, and it stuck on, it would need to run for about 2 weeks before it would overflow my sump. Not that this is related to the Puratek, but I also use my Apex to pull the ATO offline if the salinity gets below a certain amount.

With all of that being said, I will be getting the Apex ATO once it is released. It will have backups and I'll also be able to program a max runtime.

@Terence I just hope the Neptune FMM fits in place of the Puratek

IMG_7158 by Toby Broadfield, on Flickr

revhtree · Dec 21, 2016

Terence said:
I think you can see some MACNA video out there of a gray and orange one that should be out pretty soon... [emoji41]

How about posting it here? That's allowed..

Coastie Reefer · Dec 21, 2016

Smart ATO. I have the micro version and LOVE it!

JBradford · Dec 21, 2016

I use the Micro SmartATO system. I don't have any rust issues.

-3 things I like about it, one has been mentioned, the beeping when the reserve is dry which can keep you from burning up a pump.
-It will also beep if it runs for longer than the very first time you ran it. For instance, you hook it up and the first time it runs it tops off in 1 minute (pulling numbers out of thin air), if the next time it take 1 minute and 5 seconds it will beep at you because to it something is wrong.
-And it just works. I've yet to have an issue with it

Coastie Reefer · Dec 21, 2016

JBradford said:
I use the Micro SmartATO system. I don't have any rust issues.

-3 things I like about it, one has been mentioned, the beeping when the reserve is dry which can keep you from burning up a pump.
-It will also beep if it runs for longer than the very first time you ran it. For instance, you hook it up and the first time it runs it tops off in 1 minute (pulling numbers out of thin air), if the next time it take 1 minute and 5 seconds it will beep at you because to it something is wrong.
-And it just works. I've yet to have an issue with it

Not only will it beep, but it will shut off to prevent flooding too!